一、数据运算
举个例子一目了然就明白什么是运算符了；例子10+20=30，其中10,20为操作符 ，“+” 称为运算符。
python支持支持的类型运算符有：算术运算、比较（关系）运算符、赋值运算符、逻辑运算符、位运算符、成员运算符、身份运算符、运算符优先级，下面我们一个个来看。
1、算数运算：
假设变量a=10,变量b=20：
| 运算符 | 描述 | 实例 |
|---|---|---|
| + | 加 - 两个对象相加 | a + b 输出结果 30 |
| - | 减 - 得到负数或是一个数减去另一个数 | a - b 输出结果 -10 |
| * | 乘 - 两个数相乘或是返回一个被重复若干次的字符串 | a * b 输出结果 200 |
| / | 除 - x除以y | b / a 输出结果 2 |
| % | 取模 - 返回除法的余数 | b % a 输出结果 0 |
| ** | 幂 - 返回x的y次幂 | a**b 为10的20次方， 输出结果 100000000000000000000 |
| // | 取整除 - 返回商的整数部分 | 9//2 输出结果 4 , 9.0//2.0 输出结果 4.0 |
练习实例：
1 #!/usr/bin/env python 2 # -*- coding :utf-8 -*- 3 4 a = 10 5 b = 20 6 7 c = a + b #两数相加 8 print(c) 9 10 c = a - b #两数相减 11 print(c) 12 13 c = a * b #两数相乘 14 print(c) 15 16 c = a / b #两数相除 17 print(c) 18 19 c = a % b #取模,返回除法的余数 20 print(c) 21 22 c = a ** b #幂(次方) 23 print(c) 24 25 c = a // b #取整数,返回商的整数部分 26 print(c)
以上练习实例执行结果
1 C:PythonPython35python.exe E:/Python课程/s13/day2/运算符.py 2 30 3 -10 4 200 5 0.5 6 10 7 100000000000000000000 8 0 9 10 Process finished with exit code 0
2、比较运算符：
| 运算符 | 描述 | 实例 |
|---|---|---|
| == | 等于 - 比较对象是否相等 | (a == b) 返回 False。 |
| != | 不等于 - 比较两个对象是否不相等 | (a != b) 返回 true. |
| <> | 不等于 - 比较两个对象是否不相等（一般都用!=，在python3中已被移除） | (a <> b) 返回 true。这个运算符类似 != 。 |
| > | 大于 - 返回x是否大于y | (a > b) 返回 False。 |
| < | 小于 - 返回x是否小于y。所有比较运算符返回1表示真，返回0表示假。这分别与特殊的变量True和False等价。注意，这些变量名的大写。 | (a < b) 返回 true。 |
| >= | 大于等于 - 返回x是否大于等于y。 | (a >= b) 返回 False。 |
| <= | 小于等于 - 返回x是否小于等于y。 | (a <= b) 返回 true。 |
实例练习：
1 a=66 2 b=88 3 c=0 4 5 a = 10 6 b = 20 7 8 9 if (a == b): #等于 10 print('a等于b') 11 else: 12 print('a不等于b') 13 14 if (a != b): #不等于 15 print('a不等于b') 16 else: 17 print('a等于b') 18 19 # if (a <> b): #不等于(python2.x) 20 # print('a不等于b') 21 # else: 22 # print('a等于b') 23 24 25 if (a < b): #小于 26 print('a小于b') 27 else: 28 print('a不小于b') 29 30 if (a > b): #大于 31 print('a大于b') 32 else: 33 print('a不大于b ') 34 35 36 if (a <= b): #小于等于 37 print('a小于等于b') 38 else: 39 print('不对') 40 41 if (a >= b): #大于等于 42 print('a大于等于b') 43 else: 44 print('不对')
以上实例执行结果：
C:PythonPython35python.exe E:/Python课程/s13/day2/运算符.py
错误
a不等于b
错误
a小于b
错误
a小于等于b
Process finished with exit code 0
3、赋值运算符：
| 运算符 | 描述 | 实例 |
|---|---|---|
| = | 简单的赋值运算符 | c = a + b 将 a + b 的运算结果赋值为 c |
| += | 加法赋值运算符 | c += a 等效于 c = c + a |
| -= | 减法赋值运算符 | c -= a 等效于 c = c - a |
| *= | 乘法赋值运算符 | c *= a 等效于 c = c * a |
| /= | 除法赋值运算符 | c /= a 等效于 c = c / a |
| %= | 取模赋值运算符 | c %= a 等效于 c = c % a |
| **= | 幂赋值运算符 | c **= a 等效于 c = c ** a |
| //= | 取整除赋值运算符 | c //= a 等效于 c = c // a |
实例练习：
1 a = 2 2 b = 3 3 c = 0 4 5 c = a + b #把a+b的变量和赋值给c变量 6 print(c) 7 8 c += a #意思是c = c + a 9 print(c) 10 11 c -= a #意思是c = c - a 12 print(c) 13 14 c *= a #意思是c = c * a 15 print(c) 16 17 c /= a #意思是c = c / a 18 print(c) 19 20 c %= a #意思是c = c % a 21 print(c) 22 23 c **= a #意思是c = c ** a 24 print(c) 25 26 c //= a #意思是c = c // a 27 print(c)
以上实例执行结果：
1 C:PythonPython35python.exe E:/Python课程/s13/day2/运算符.py 2 5 3 7 4 5 5 10 6 5.0 7 1.0 8 1.0 9 0.0 10 11 Process finished with exit code 0
4、位运算符：
执行二进制运算
| 运算符 | 描述 | 实例 |
|---|---|---|
| & | 按位与运算符：参与运算的两个值,如果两个相应位都为1,则该位的结果为1,否则为0 | (a & b) 输出结果 12 ，二进制解释： 0000 1100 |
| | | 按位或运算符：只要对应的二个二进位有一个为1时，结果位就为1。 | (a | b) 输出结果 61 ，二进制解释： 0011 1101 |
| ^ | 按位异或运算符：当两对应的二进位相异时，结果为1 | (a ^ b) 输出结果 49 ，二进制解释： 0011 0001 |
| ~ | 按位取反运算符：对数据的每个二进制位取反,即把1变为0,把0变为1 | (~a ) 输出结果 -61 ，二进制解释： 1100 0011， 在一个有符号二进制数的补码形式。 |
| << | 左移动运算符：运算数的各二进位全部左移若干位，由"<<"右边的数指定移动的位数，高位丢弃，低位补0。 | a << 2 输出结果 240 ，二进制解释： 1111 0000 |
| >> | 右移动运算符：把">>"左边的运算数的各二进位全部右移若干位，">>"右边的数指定移动的位数 | a >> 2 输出结果 15 ，二进制解释： 0000 1111 |
实例练习：
#!/usr/bin/env python3 a = 10 b = 60 c = 0 #一下是数字转成二进制的方法 #例如取10,60数字的二进制 #128 64 32 16 8 4 2 1 #0 0 0 0 1 0 1 0 = 10 #0 0 1 1 1 1 0 0 = 60 #0 0 0 0 1 0 0 0 = 8 # # 所以数字10,60,的二进制分别为 # 10 = 1010 # 60 = 111100 c = a & b #按位与运算符:二进制位置中相对应的为1的则为1,否则为0 print(c) #128 64 32 16 8 4 2 1 #0 0 0 0 1 0 1 0 = a = 10 #0 0 1 1 1 1 0 0 = b = 60 #0 0 0 0 1 0 0 0 = c = a & b = 8 c = a | b #按位或运算符:只要对应的位置是1的时候就是1 print(c) #128 64 32 16 8 4 2 1 #0 0 0 0 1 0 1 0 = a = 10 #0 0 1 1 1 1 0 0 = b = 60 #0 0 1 1 1 1 1 0 = c = a | b = 62 c = a ^ b #按位异或运算符:就是相对应的位置不一样的时候等于1 print(c) #128 64 32 16 8 4 2 1 #0 0 0 0 1 0 1 0 = a = 10 #0 0 1 1 1 1 0 0 = b = 60 #0 0 1 1 0 1 1 0 = c = a ^ b = 54 c = a << 2 #做移动运算符:往左边移动两位相当于 10*（2**2）左移n位就是乘以2的n次方 print(c) #128 64 32 16 8 4 2 1 #0 0 0 0 1 0 1 0 = a = 10 #0 0 1 0 1 0 0 0 = c = a << 2 = 40 c = a >> 2 #右移动运算符:往右边移动两位 print(c) #128 64 32 16 8 4 2 1 #0 0 0 0 1 0 1 0 = a = 10 #0 0 0 0 0 0 1 0 = c = a >>2 = 2
以上事例执行结果：
C:PythonPython35python.exe E:/Python课程/s13/day2/运算符.py 8 62 54 40 2 Process finished with exit code 0
5、逻辑运算符：
假设变量 a 为 10, b为 20:
| 运算符 | 逻辑表达式 | 描述 | 实例 |
|---|---|---|---|
| and | x and y | 布尔"与" - 如果 x 为 False，x and y 返回 False，否则它返回 y 的计算值。 | (a and b) 返回 20 |
| or | x or y | 布尔"或" - 如果 x 是 True，它返回 True，否则它返回 y 的计算值。 | (a or b) 返回 10 |
| not | not x | 布尔"非" - 如果 x 为 True，返回 False 。如果 x 为 False，它返回 True。 | not(a and b) 返回 False |
6、成员运算符：
| 运算符 | 描述 | 实例 |
|---|---|---|
| in | 如果在指定的序列中找到值返回 True，否则返回 False。 | x 在 y 序列中 , 如果 x 在 y 序列中返回 True。 |
| not in | 如果在指定的序列中没有找到值返回 True，否则返回 False。 | x 不在 y 序列中 , 如果 x 不在 y 序列中返回 True。 |
二、数据类型：
1、数字数据类型
包含四种：
int整型 如：23、333
long长整型：就是比较大比较长的数字
在32位机器上，整数的位数为32位，取值范围为-2**31～2**31-1，即-2147483648～2147483647
在64位系统上，整数的位数为64位，取值范围为-2**63～2**63-1，即-9223372036854775808～9223372036854775807
大于以上范围着都属于长整型，只不过局限于python2中，在python3中已经不存在了！
float（浮点型）：顾名思义就是带有小数点的数字，占8个字节（64位），其中52位表示底，11位表示指数，剩下的一位表示符号。
complex（复数）：复数由实数部分和虚数部分组成，一般形式为x＋yj，其中的x是复数的实数部分，y是复数的虚数部分，这里的x和y都是实数。
注：Python中存在小数字池：-5 ～ 257
其中使用的函数：
| abs(x) | 返回数字的绝对值，如abs(-10) 返回 10 |
2、布尔值
真或假（Ture、False）
1 或 0
3、字符串（str）
例如："hello world" 这就是字符串，其中字符串有很多种用法如下：
1 class str(basestring): 2 """ 3 str(object='') -> string 4 5 Return a nice string representation of the object. 6 If the argument is a string, the return value is the same object. 7 """ 8 def capitalize(self): 9 """ 首字母变大写 """ 10 """ 11 S.capitalize() -> string 12 13 Return a copy of the string S with only its first character 14 capitalized. 15 """ 16 return "" 17 18 def center(self, width, fillchar=None): 19 """ 内容居中，width：总长度；fillchar：空白处填充内容，默认无 """ 20 """ 21 S.center(width[, fillchar]) -> string 22 23 Return S centered in a string of length width. Padding is 24 done using the specified fill character (default is a space) 25 """ 26 return "" 27 28 def count(self, sub, start=None, end=None): 29 """ 子序列个数 """ 30 """ 31 S.count(sub[, start[, end]]) -> int 32 33 Return the number of non-overlapping occurrences of substring sub in 34 string S[start:end]. Optional arguments start and end are interpreted 35 as in slice notation. 36 """ 37 return 0 38 39 def decode(self, encoding=None, errors=None): 40 """ 解码 """ 41 """ 42 S.decode([encoding[,errors]]) -> object 43 44 Decodes S using the codec registered for encoding. encoding defaults 45 to the default encoding. errors may be given to set a different error 46 handling scheme. Default is 'strict' meaning that encoding errors raise 47 a UnicodeDecodeError. Other possible values are 'ignore' and 'replace' 48 as well as any other name registered with codecs.register_error that is 49 able to handle UnicodeDecodeErrors. 50 """ 51 return object() 52 53 def encode(self, encoding=None, errors=None): 54 """ 编码，针对unicode """ 55 """ 56 S.encode([encoding[,errors]]) -> object 57 58 Encodes S using the codec registered for encoding. encoding defaults 59 to the default encoding. errors may be given to set a different error 60 handling scheme. Default is 'strict' meaning that encoding errors raise 61 a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and 62 'xmlcharrefreplace' as well as any other name registered with 63 codecs.register_error that is able to handle UnicodeEncodeErrors. 64 """ 65 return object() 66 67 def endswith(self, suffix, start=None, end=None): 68 """ 是否以 xxx 结束 """ 69 """ 70 S.endswith(suffix[, start[, end]]) -> bool 71 72 Return True if S ends with the specified suffix, False otherwise. 73 With optional start, test S beginning at that position. 74 With optional end, stop comparing S at that position. 75 suffix can also be a tuple of strings to try. 76 """ 77 return False 78 79 def expandtabs(self, tabsize=None): 80 """ 将tab转换成空格，默认一个tab转换成8个空格 """ 81 """ 82 S.expandtabs([tabsize]) -> string 83 84 Return a copy of S where all tab characters are expanded using spaces. 85 If tabsize is not given, a tab size of 8 characters is assumed. 86 """ 87 return "" 88 89 def find(self, sub, start=None, end=None): 90 """ 寻找子序列位置，如果没找到，返回 -1 """ 91 """ 92 S.find(sub [,start [,end]]) -> int 93 94 Return the lowest index in S where substring sub is found, 95 such that sub is contained within S[start:end]. Optional 96 arguments start and end are interpreted as in slice notation. 97 98 Return -1 on failure. 99 """ 100 return 0 101 102 def format(*args, **kwargs): # known special case of str.format 103 """ 字符串格式化，动态参数，将函数式编程时细说 """ 104 """ 105 S.format(*args, **kwargs) -> string 106 107 Return a formatted version of S, using substitutions from args and kwargs. 108 The substitutions are identified by braces ('{' and '}'). 109 """ 110 pass 111 112 def index(self, sub, start=None, end=None): 113 """ 子序列位置，如果没找到，报错 """ 114 S.index(sub [,start [,end]]) -> int 115 116 Like S.find() but raise ValueError when the substring is not found. 117 """ 118 return 0 119 120 def isalnum(self): 121 """ 是否是字母和数字 """ 122 """ 123 S.isalnum() -> bool 124 125 Return True if all characters in S are alphanumeric 126 and there is at least one character in S, False otherwise. 127 """ 128 return False 129 130 def isalpha(self): 131 """ 是否是字母 """ 132 """ 133 S.isalpha() -> bool 134 135 Return True if all characters in S are alphabetic 136 and there is at least one character in S, False otherwise. 137 """ 138 return False 139 140 def isdigit(self): 141 """ 是否是数字 """ 142 """ 143 S.isdigit() -> bool 144 145 Return True if all characters in S are digits 146 and there is at least one character in S, False otherwise. 147 """ 148 return False 149 150 def islower(self): 151 """ 是否小写 """ 152 """ 153 S.islower() -> bool 154 155 Return True if all cased characters in S are lowercase and there is 156 at least one cased character in S, False otherwise. 157 """ 158 return False 159 160 def isspace(self): 161 """ 162 S.isspace() -> bool 163 164 Return True if all characters in S are whitespace 165 and there is at least one character in S, False otherwise. 166 """ 167 return False 168 169 def istitle(self): 170 """ 171 S.istitle() -> bool 172 173 Return True if S is a titlecased string and there is at least one 174 character in S, i.e. uppercase characters may only follow uncased 175 characters and lowercase characters only cased ones. Return False 176 otherwise. 177 """ 178 return False 179 180 def isupper(self): 181 """ 182 S.isupper() -> bool 183 184 Return True if all cased characters in S are uppercase and there is 185 at least one cased character in S, False otherwise. 186 """ 187 return False 188 189 def join(self, iterable): 190 """ 连接 """ 191 """ 192 S.join(iterable) -> string 193 194 Return a string which is the concatenation of the strings in the 195 iterable. The separator between elements is S. 196 """ 197 return "" 198 199 def ljust(self, width, fillchar=None): 200 """ 内容左对齐，右侧填充 """ 201 """ 202 S.ljust(width[, fillchar]) -> string 203 204 Return S left-justified in a string of length width. Padding is 205 done using the specified fill character (default is a space). 206 """ 207 return "" 208 209 def lower(self): 210 """ 变小写 """ 211 """ 212 S.lower() -> string 213 214 Return a copy of the string S converted to lowercase. 215 """ 216 return "" 217 218 def lstrip(self, chars=None): 219 """ 移除左侧空白 """ 220 """ 221 S.lstrip([chars]) -> string or unicode 222 223 Return a copy of the string S with leading whitespace removed. 224 If chars is given and not None, remove characters in chars instead. 225 If chars is unicode, S will be converted to unicode before stripping 226 """ 227 return "" 228 229 def partition(self, sep): 230 """ 分割，前，中，后三部分 """ 231 """ 232 S.partition(sep) -> (head, sep, tail) 233 234 Search for the separator sep in S, and return the part before it, 235 the separator itself, and the part after it. If the separator is not 236 found, return S and two empty strings. 237 """ 238 pass 239 240 def replace(self, old, new, count=None): 241 """ 替换 """ 242 """ 243 S.replace(old, new[, count]) -> string 244 245 Return a copy of string S with all occurrences of substring 246 old replaced by new. If the optional argument count is 247 given, only the first count occurrences are replaced. 248 """ 249 return "" 250 251 def rfind(self, sub, start=None, end=None): 252 """ 253 S.rfind(sub [,start [,end]]) -> int 254 255 Return the highest index in S where substring sub is found, 256 such that sub is contained within S[start:end]. Optional 257 arguments start and end are interpreted as in slice notation. 258 259 Return -1 on failure. 260 """ 261 return 0 262 263 def rindex(self, sub, start=None, end=None): 264 """ 265 S.rindex(sub [,start [,end]]) -> int 266 267 Like S.rfind() but raise ValueError when the substring is not found. 268 """ 269 return 0 270 271 def rjust(self, width, fillchar=None): 272 """ 273 S.rjust(width[, fillchar]) -> string 274 275 Return S right-justified in a string of length width. Padding is 276 done using the specified fill character (default is a space) 277 """ 278 return "" 279 280 def rpartition(self, sep): 281 """ 282 S.rpartition(sep) -> (head, sep, tail) 283 284 Search for the separator sep in S, starting at the end of S, and return 285 the part before it, the separator itself, and the part after it. If the 286 separator is not found, return two empty strings and S. 287 """ 288 pass 289 290 def rsplit(self, sep=None, maxsplit=None): 291 """ 292 S.rsplit([sep [,maxsplit]]) -> list of strings 293 294 Return a list of the words in the string S, using sep as the 295 delimiter string, starting at the end of the string and working 296 to the front. If maxsplit is given, at most maxsplit splits are 297 done. If sep is not specified or is None, any whitespace string 298 is a separator. 299 """ 300 return [] 301 302 def rstrip(self, chars=None): 303 """ 304 S.rstrip([chars]) -> string or unicode 305 306 Return a copy of the string S with trailing whitespace removed. 307 If chars is given and not None, remove characters in chars instead. 308 If chars is unicode, S will be converted to unicode before stripping 309 """ 310 return "" 311 312 def split(self, sep=None, maxsplit=None): 313 """ 分割， maxsplit最多分割几次 """ 314 """ 315 S.split([sep [,maxsplit]]) -> list of strings 316 317 Return a list of the words in the string S, using sep as the 318 delimiter string. If maxsplit is given, at most maxsplit 319 splits are done. If sep is not specified or is None, any 320 whitespace string is a separator and empty strings are removed 321 from the result. 322 """ 323 return [] 324 325 def splitlines(self, keepends=False): 326 """ 根据换行分割 """ 327 """ 328 S.splitlines(keepends=False) -> list of strings 329 330 Return a list of the lines in S, breaking at line boundaries. 331 Line breaks are not included in the resulting list unless keepends 332 is given and true. 333 """ 334 return [] 335 336 def startswith(self, prefix, start=None, end=None): 337 """ 是否起始 """ 338 """ 339 S.startswith(prefix[, start[, end]]) -> bool 340 341 Return True if S starts with the specified prefix, False otherwise. 342 With optional start, test S beginning at that position. 343 With optional end, stop comparing S at that position. 344 prefix can also be a tuple of strings to try. 345 """ 346 return False 347 348 def strip(self, chars=None): 349 """ 移除两段空白 """ 350 """ 351 S.strip([chars]) -> string or unicode 352 353 Return a copy of the string S with leading and trailing 354 whitespace removed. 355 If chars is given and not None, remove characters in chars instead. 356 If chars is unicode, S will be converted to unicode before stripping 357 """ 358 return "" 359 360 def swapcase(self): 361 """ 大写变小写，小写变大写 """ 362 """ 363 S.swapcase() -> string 364 365 Return a copy of the string S with uppercase characters 366 converted to lowercase and vice versa. 367 """ 368 return "" 369 370 def title(self): 371 """ 372 S.title() -> string 373 374 Return a titlecased version of S, i.e. words start with uppercase 375 characters, all remaining cased characters have lowercase. 376 """ 377 return "" 378 379 def translate(self, table, deletechars=None): 380 """ 381 转换，需要先做一个对应表，最后一个表示删除字符集合 382 intab = "aeiou" 383 outtab = "12345" 384 trantab = maketrans(intab, outtab) 385 str = "this is string example....wow!!!" 386 print str.translate(trantab, 'xm') 387 """ 388 389 """ 390 S.translate(table [,deletechars]) -> string 391 392 Return a copy of the string S, where all characters occurring 393 in the optional argument deletechars are removed, and the 394 remaining characters have been mapped through the given 395 translation table, which must be a string of length 256 or None. 396 If the table argument is None, no translation is applied and 397 the operation simply removes the characters in deletechars. 398 """ 399 return "" 400 401 def upper(self): 402 """ 403 S.upper() -> string 404 405 Return a copy of the string S converted to uppercase. 406 """ 407 return "" 408 409 def zfill(self, width): 410 """方法返回指定长度的字符串，原字符串右对齐，前面填充0。""" 411 """ 412 S.zfill(width) -> string 413 414 Pad a numeric string S with zeros on the left, to fill a field 415 of the specified width. The string S is never truncated. 416 """ 417 return "" 418 419 def _formatter_field_name_split(self, *args, **kwargs): # real signature unknown 420 pass 421 422 def _formatter_parser(self, *args, **kwargs): # real signature unknown 423 pass 424 425 def __add__(self, y): 426 """ x.__add__(y) <==> x+y """ 427 pass 428 429 def __contains__(self, y): 430 """ x.__contains__(y) <==> y in x """ 431 pass 432 433 def __eq__(self, y): 434 """ x.__eq__(y) <==> x==y """ 435 pass 436 437 def __format__(self, format_spec): 438 """ 439 S.__format__(format_spec) -> string 440 441 Return a formatted version of S as described by format_spec. 442 """ 443 return "" 444 445 def __getattribute__(self, name): 446 """ x.__getattribute__('name') <==> x.name """ 447 pass 448 449 def __getitem__(self, y): 450 """ x.__getitem__(y) <==> x[y] """ 451 pass 452 453 def __getnewargs__(self, *args, **kwargs): # real signature unknown 454 pass 455 456 def __getslice__(self, i, j): 457 """ 458 x.__getslice__(i, j) <==> x[i:j] 459 460 Use of negative indices is not supported. 461 """ 462 pass 463 464 def __ge__(self, y): 465 """ x.__ge__(y) <==> x>=y """ 466 pass 467 468 def __gt__(self, y): 469 """ x.__gt__(y) <==> x>y """ 470 pass 471 472 def __hash__(self): 473 """ x.__hash__() <==> hash(x) """ 474 pass 475 476 def __init__(self, string=''): # known special case of str.__init__ 477 """ 478 str(object='') -> string 479 480 Return a nice string representation of the object. 481 If the argument is a string, the return value is the same object. 482 # (copied from class doc) 483 """ 484 pass 485 486 def __len__(self): 487 """ x.__len__() <==> len(x) """ 488 pass 489 490 def __le__(self, y): 491 """ x.__le__(y) <==> x<=y """ 492 pass 493 494 def __lt__(self, y): 495 """ x.__lt__(y) <==> x<y """ 496 pass 497 498 def __mod__(self, y): 499 """ x.__mod__(y) <==> x%y """ 500 pass 501 502 def __mul__(self, n): 503 """ x.__mul__(n) <==> x*n """ 504 pass 505 506 @staticmethod # known case of __new__ 507 def __new__(S, *more): 508 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 509 pass 510 511 def __ne__(self, y): 512 """ x.__ne__(y) <==> x!=y """ 513 pass 514 515 def __repr__(self): 516 """ x.__repr__() <==> repr(x) """ 517 pass 518 519 def __rmod__(self, y): 520 """ x.__rmod__(y) <==> y%x """ 521 pass 522 523 def __rmul__(self, n): 524 """ x.__rmul__(n) <==> n*x """ 525 pass 526 527 def __sizeof__(self): 528 """ S.__sizeof__() -> size of S in memory, in bytes """ 529 pass 530 531 def __str__(self): 532 """ x.__str__() <==> str(x) """ 533 pass 534 535 str 536 537 str
具体使用特别列出来了几个:
1 name="tianjie" 2 print(type(name)) #显示数据是什么类型 3 4 name="tianjie" 5 names=name.__contains__("jie") #字符“jie” 是否在对象中 6 7 name="asdasdasdasdasdasd" 8 names=name.count("as",0,9) #统计在对象0-9索引中“as”字符有几个 9 print(names) 10 11 name="tianjie" 12 names=name.center(20,"*") #宽数20居中，并且两边是“*”默认是空 13 print(names) 14 15 name="田杰" 16 names=name.encode("gbk") #转换字符编码 17 print(names) 18 19 name="tianjie" 20 names=name.capitalize() #首字母改为大写 21 names=name.endswith("ie",0,8) #0-8索引“ie”结尾 22 print(names) 23 24 name="tianjie" 25 #names=name.find("j") # #查找“j”在对象中的第一个下标 26 names=name.find("an") 27 print(names)
name="tianjieandxiaobai"
names=name.partition("and") #把对象name以“and” 为中心分成三段
print(names)
name="asdfasdfasdfasdfasdsa"
names=name.replace("a","w") #把对象name中的"a"全部替换成"w"
names=name.replace("a","w",3) #把对象name中的“a”前三个替换成“w”
print(names)
万恶的字符串拼接就是“+”：
python中的字符串在C语言中体现为是一个字符数组，每次创建字符串时候需要在内存中开辟一块连续的空，并且一旦需要修改字符串的话，就需要再次开辟空间，万恶的+号每出现一次就会在内从中重新开辟一块空间。
字符串格式化：
1 name = input("name:") 2 age = input("age:") 3 job = input("job:") 4 5 #print("Infomation of []:" + name + " Name:[]" + name +" Age:[]" + age +" Job:[]"+ job )#万恶的“+” 说的就是这个 6 #print("Infomation of :%s Name:%s Job:%s" %(name,name,age,job)) #土鳖写法格式 7 8 test = ''' 9 Infomation of :%s 10 Name:%s 11 age:%s 12 Job:%s 13 ''' %(name,name,age,job) #这种写法格式才是高大上 14 print(test)
4、列表 *
书写格式如：[1,2,3,"qwe",[123,"q"]],列表里可以包含任何数据，数字、字符、变量、也可以包含列表、字典、元组等。
序列都可以进行的操作包括索引，切片，加，乘，检查成员，而且是有序的
功能如下：
1 class list(object): 2 """ 3 list() -> new empty list 4 list(iterable) -> new list initialized from iterable's items 5 """ 6 def append(self, p_object): # real signature unknown; restored from __doc__ 7 """ L.append(object) -- append object to end """ 8 pass 9 10 def count(self, value): # real signature unknown; restored from __doc__ 11 """ L.count(value) -> integer -- return number of occurrences of value """ 12 return 0 13 14 def extend(self, iterable): # real signature unknown; restored from __doc__ 15 """ L.extend(iterable) -- extend list by appending elements from the iterable """ 16 pass 17 18 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__ 19 """ 20 L.index(value, [start, [stop]]) -> integer -- return first index of value. 21 Raises ValueError if the value is not present. 22 """ 23 return 0 24 25 def insert(self, index, p_object): # real signature unknown; restored from __doc__ 26 """ L.insert(index, object) -- insert object before index """ 27 pass 28 29 def pop(self, index=None): # real signature unknown; restored from __doc__ 30 """ 31 L.pop([index]) -> item -- remove and return item at index (default last). 32 Raises IndexError if list is empty or index is out of range. 33 """ 34 pass 35 36 def remove(self, value): # real signature unknown; restored from __doc__ 37 """ 38 L.remove(value) -- remove first occurrence of value. 39 Raises ValueError if the value is not present. 40 """ 41 pass 42 43 def reverse(self): # real signature unknown; restored from __doc__ 44 """ L.reverse() -- reverse *IN PLACE* """ 45 pass 46 47 def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__ 48 """ 49 L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*; 50 cmp(x, y) -> -1, 0, 1 51 """ 52 pass 53 54 def __add__(self, y): # real signature unknown; restored from __doc__ 55 """ x.__add__(y) <==> x+y """ 56 pass 57 58 def __contains__(self, y): # real signature unknown; restored from __doc__ 59 """ x.__contains__(y) <==> y in x """ 60 pass 61 62 def __delitem__(self, y): # real signature unknown; restored from __doc__ 63 """ x.__delitem__(y) <==> del x[y] """ 64 pass 65 66 def __delslice__(self, i, j): # real signature unknown; restored from __doc__ 67 """ 68 x.__delslice__(i, j) <==> del x[i:j] 69 70 Use of negative indices is not supported. 71 """ 72 pass 73 74 def __eq__(self, y): # real signature unknown; restored from __doc__ 75 """ x.__eq__(y) <==> x==y """ 76 pass 77 78 def __getattribute__(self, name): # real signature unknown; restored from __doc__ 79 """ x.__getattribute__('name') <==> x.name """ 80 pass 81 82 def __getitem__(self, y): # real signature unknown; restored from __doc__ 83 """ x.__getitem__(y) <==> x[y] """ 84 pass 85 86 def __getslice__(self, i, j): # real signature unknown; restored from __doc__ 87 """ 88 x.__getslice__(i, j) <==> x[i:j] 89 90 Use of negative indices is not supported. 91 """ 92 pass 93 94 def __ge__(self, y): # real signature unknown; restored from __doc__ 95 """ x.__ge__(y) <==> x>=y """ 96 pass 97 98 def __gt__(self, y): # real signature unknown; restored from __doc__ 99 """ x.__gt__(y) <==> x>y """ 100 pass 101 102 def __iadd__(self, y): # real signature unknown; restored from __doc__ 103 """ x.__iadd__(y) <==> x+=y """ 104 pass 105 106 def __imul__(self, y): # real signature unknown; restored from __doc__ 107 """ x.__imul__(y) <==> x*=y """ 108 pass 109 110 def __init__(self, seq=()): # known special case of list.__init__ 111 """ 112 list() -> new empty list 113 list(iterable) -> new list initialized from iterable's items 114 # (copied from class doc) 115 """ 116 pass 117 118 def __iter__(self): # real signature unknown; restored from __doc__ 119 """ x.__iter__() <==> iter(x) """ 120 pass 121 122 def __len__(self): # real signature unknown; restored from __doc__ 123 """ x.__len__() <==> len(x) """ 124 pass 125 126 def __le__(self, y): # real signature unknown; restored from __doc__ 127 """ x.__le__(y) <==> x<=y """ 128 pass 129 130 def __lt__(self, y): # real signature unknown; restored from __doc__ 131 """ x.__lt__(y) <==> x<y """ 132 pass 133 134 def __mul__(self, n): # real signature unknown; restored from __doc__ 135 """ x.__mul__(n) <==> x*n """ 136 pass 137 138 @staticmethod # known case of __new__ 139 def __new__(S, *more): # real signature unknown; restored from __doc__ 140 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 141 pass 142 143 def __ne__(self, y): # real signature unknown; restored from __doc__ 144 """ x.__ne__(y) <==> x!=y """ 145 pass 146 147 def __repr__(self): # real signature unknown; restored from __doc__ 148 """ x.__repr__() <==> repr(x) """ 149 pass 150 151 def __reversed__(self): # real signature unknown; restored from __doc__ 152 """ L.__reversed__() -- return a reverse iterator over the list """ 153 pass 154 155 def __rmul__(self, n): # real signature unknown; restored from __doc__ 156 """ x.__rmul__(n) <==> n*x """ 157 pass 158 159 def __setitem__(self, i, y): # real signature unknown; restored from __doc__ 160 """ x.__setitem__(i, y) <==> x[i]=y """ 161 pass 162 163 def __setslice__(self, i, j, y): # real signature unknown; restored from __doc__ 164 """ 165 x.__setslice__(i, j, y) <==> x[i:j]=y 166 167 Use of negative indices is not supported. 168 """ 169 pass 170 171 def __sizeof__(self): # real signature unknown; restored from __doc__ 172 """ L.__sizeof__() -- size of L in memory, in bytes """ 173 pass 174 175 __hash__ = None 176 177 list
具体用法：
1 name=[1,2,3] 2 name.extend(["g","k",]) #合并，也可以合并一个列表 3 4 k=name.pop(0) #取出指定索引的元素，默认是最后一个元素，把取出来的元素在重新赋值 5 print(k) 6 7 name=[1,2,3,"q","a"] 8 name.reverse() #翻转，顺序颠倒 9 10 name.append("tianjie") #追加，在末尾添加 11 12 name.remove("a") # 指定删除哪个元素 13 14 name.insert(3,"xiaobai") #在指定下标后添加 15 16 name.index("q") #取出指定下标 17 18 name.count("a") #统计a在列表name中出现的次数 19 20 namel.sort() #排序，但是字符转不能与数字在一起排序 21 22 name.clear() #清空列表 23 24 name.copy() #复制，这里的复制指的是浅复制
实例1练习：
1 创建个列表 2 name=["潘文斌","田杰","杩栋胜","潘东林","牛恒博","杜保强","梁连","赵鸿飞" ] 3 4 #新添加元素 5 name.insert(4,"张三") 6 name.insert(5,"李四") 7 8 #取出第3-8之间的人 9 print(name[2:8]) 10 11 #一次删除新添的两个名字 12 for i in name[4:6]: 13 name.remove(i) 14 print(name) 15 #或者del name[4:6] 16 17 #删除第7个人 18 name.pop(7) 19 20 #更改元素 21 name[0]="潘文斌组长" 22 #隔一个人打印一个人 23 print(name[::2])
练习2：
创建列表如： name=[6,6,4,564,5,6,56,45,6,45,64,56,45,6,655,5,56,2,2,2,34,2,34,6,6,4,4,4,4,5,5] 1、把列表中数字6全部换成6666 2、把列表中数字4全部删掉
1 name=[6,6,4,564,5,6,56,45,6,45,64,56,45,6,655,5,56,2,2,2,34,2,34,6,6,4,4,4,4,5,5] 2 count=name.count(6) 3 4 for i in range(name.count(6)): 5 nums=name.index(6) 6 name[nums]=6666 7 8 for i in range(name.count(4)): 9 nums1=name.index(4) 10 name.pop(nums1) 11 12 print(name)
练习3：
练习：元素分类 有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，将所有大于 66 的值保存至字典的第一个key中，将小于 66 的值保存至第二个key的值中。 即： {'k1': 大于66 , 'k2': 小于66}
1 li=[11,22,33,44,55,66,77,88,99] 2 dic={} 3 a=[] 4 b=[] 5 for i in li: 6 if i>66: 7 a.append(i) 8 else: 9 b.append(1) 10 dic["k1"]=a 11 dic["k2"]=b 12 print(dic)
5、元组
我的理解就是，不能修改，添加，删除的列表
书写格式:("qwe","asd",1,2,3,4)
功能如下：
1 class tuple(object): 2 """ 3 tuple() -> empty tuple 4 tuple(iterable) -> tuple initialized from iterable's items 5 6 If the argument is a tuple, the return value is the same object. 7 """ 8 def count(self, value): # real signature unknown; restored from __doc__ 9 """ T.count(value) -> integer -- return number of occurrences of value """ 10 return 0 11 12 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__ 13 """ 14 T.index(value, [start, [stop]]) -> integer -- return first index of value. 15 Raises ValueError if the value is not present. 16 """ 17 return 0 18 19 def __add__(self, y): # real signature unknown; restored from __doc__ 20 """ x.__add__(y) <==> x+y """ 21 pass 22 23 def __contains__(self, y): # real signature unknown; restored from __doc__ 24 """ x.__contains__(y) <==> y in x """ 25 pass 26 27 def __eq__(self, y): # real signature unknown; restored from __doc__ 28 """ x.__eq__(y) <==> x==y """ 29 pass 30 31 def __getattribute__(self, name): # real signature unknown; restored from __doc__ 32 """ x.__getattribute__('name') <==> x.name """ 33 pass 34 35 def __getitem__(self, y): # real signature unknown; restored from __doc__ 36 """ x.__getitem__(y) <==> x[y] """ 37 pass 38 39 def __getnewargs__(self, *args, **kwargs): # real signature unknown 40 pass 41 42 def __getslice__(self, i, j): # real signature unknown; restored from __doc__ 43 """ 44 x.__getslice__(i, j) <==> x[i:j] 45 46 Use of negative indices is not supported. 47 """ 48 pass 49 50 def __ge__(self, y): # real signature unknown; restored from __doc__ 51 """ x.__ge__(y) <==> x>=y """ 52 pass 53 54 def __gt__(self, y): # real signature unknown; restored from __doc__ 55 """ x.__gt__(y) <==> x>y """ 56 pass 57 58 def __hash__(self): # real signature unknown; restored from __doc__ 59 """ x.__hash__() <==> hash(x) """ 60 pass 61 62 def __init__(self, seq=()): # known special case of tuple.__init__ 63 """ 64 tuple() -> empty tuple 65 tuple(iterable) -> tuple initialized from iterable's items 66 67 If the argument is a tuple, the return value is the same object. 68 # (copied from class doc) 69 """ 70 pass 71 72 def __iter__(self): # real signature unknown; restored from __doc__ 73 """ x.__iter__() <==> iter(x) """ 74 pass 75 76 def __len__(self): # real signature unknown; restored from __doc__ 77 """ x.__len__() <==> len(x) """ 78 pass 79 80 def __le__(self, y): # real signature unknown; restored from __doc__ 81 """ x.__le__(y) <==> x<=y """ 82 pass 83 84 def __lt__(self, y): # real signature unknown; restored from __doc__ 85 """ x.__lt__(y) <==> x<y """ 86 pass 87 88 def __mul__(self, n): # real signature unknown; restored from __doc__ 89 """ x.__mul__(n) <==> x*n """ 90 pass 91 92 @staticmethod # known case of __new__ 93 def __new__(S, *more): # real signature unknown; restored from __doc__ 94 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 95 pass 96 97 def __ne__(self, y): # real signature unknown; restored from __doc__ 98 """ x.__ne__(y) <==> x!=y """ 99 pass 100 101 def __repr__(self): # real signature unknown; restored from __doc__ 102 """ x.__repr__() <==> repr(x) """ 103 pass 104 105 def __rmul__(self, n): # real signature unknown; restored from __doc__ 106 """ x.__rmul__(n) <==> n*x """ 107 pass 108 109 def __sizeof__(self): # real signature unknown; restored from __doc__ 110 """ T.__sizeof__() -- size of T in memory, in bytes """ 111 pass 112 113 tuple
常用的工就两个：
1 name=(1,2,3,4,"q","e","c") 2 name.index("q") #查看下标 3 name.count("e") #统计
6、字典
字典的每个键值(key=>value)对用冒号(:)分割，每个对之间用逗号(,)分割，整个字典包括在花括号({})中，格式如下：
{"name":"tianjie","age":18}
{"host":'192.168.1.2',"port":80}
注：循环时默认循环key
功能如下：
1 class dict(object): 2 """ 3 dict() -> new empty dictionary 4 dict(mapping) -> new dictionary initialized from a mapping object's 5 (key, value) pairs 6 dict(iterable) -> new dictionary initialized as if via: 7 d = {} 8 for k, v in iterable: 9 d[k] = v 10 dict(**kwargs) -> new dictionary initialized with the name=value pairs 11 in the keyword argument list. For example: dict(one=1, two=2) 12 """ 13 14 def clear(self): # real signature unknown; restored from __doc__ 15 """ 清除内容 """ 16 """ D.clear() -> None. Remove all items from D. """ 17 pass 18 19 def copy(self): # real signature unknown; restored from __doc__ 20 """ 浅拷贝 """ 21 """ D.copy() -> a shallow copy of D """ 22 pass 23 24 @staticmethod # known case 25 def fromkeys(S, v=None): # real signature unknown; restored from __doc__ 26 """ 27 dict.fromkeys(S[,v]) -> New dict with keys from S and values equal to v. 28 v defaults to None. 29 """ 30 pass 31 32 def get(self, k, d=None): # real signature unknown; restored from __doc__ 33 """ 根据key获取值，d是默认值 """ 34 """ D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None. """ 35 pass 36 37 def has_key(self, k): # real signature unknown; restored from __doc__ 38 """ 是否有key python3中移除 """ 39 """ D.has_key(k) -> True if D has a key k, else False """ 40 return False 41 42 def items(self): # real signature unknown; restored from __doc__ 43 """ 所有项的列表形式 """ 44 """ D.items() -> list of D's (key, value) pairs, as 2-tuples """ 45 return [] 46 47 def iteritems(self): # real signature unknown; restored from __doc__ 48 """ 项可迭代 """ 49 """ D.iteritems() -> an iterator over the (key, value) items of D """ 50 pass 51 52 def iterkeys(self): # real signature unknown; restored from __doc__ 53 """ key可迭代 """ 54 """ D.iterkeys() -> an iterator over the keys of D """ 55 pass 56 57 def itervalues(self): # real signature unknown; restored from __doc__ 58 """ value可迭代 """ 59 """ D.itervalues() -> an iterator over the values of D """ 60 pass 61 62 def keys(self): # real signature unknown; restored from __doc__ 63 """ 所有的key列表 """ 64 """ D.keys() -> list of D's keys """ 65 return [] 66 67 def pop(self, k, d=None): # real signature unknown; restored from __doc__ 68 """ 获取并在字典中移除 """ 69 """ 70 D.pop(k[,d]) -> v, remove specified key and return the corresponding value. 71 If key is not found, d is returned if given, otherwise KeyError is raised 72 """ 73 pass 74 75 def popitem(self): # real signature unknown; restored from __doc__ 76 """ 获取并在字典中移除 """ 77 """ 78 D.popitem() -> (k, v), remove and return some (key, value) pair as a 79 2-tuple; but raise KeyError if D is empty. 80 """ 81 pass 82 83 def setdefault(self, k, d=None): # real signature unknown; restored from __doc__ 84 """ 如果key不存在，则创建，如果存在，则返回已存在的值且不修改 """ 85 """ D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """ 86 pass 87 88 def update(self, E=None, **F): # known special case of dict.update 89 """ 更新 90 {'name':'alex', 'age': 18000} 91 [('name','sbsbsb'),] 92 """ 93 """ 94 D.update([E, ]**F) -> None. Update D from dict/iterable E and F. 95 If E present and has a .keys() method, does: for k in E: D[k] = E[k] 96 If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v 97 In either case, this is followed by: for k in F: D[k] = F[k] 98 """ 99 pass 100 101 def values(self): # real signature unknown; restored from __doc__ 102 """ 所有的值 """ 103 """ D.values() -> list of D's values """ 104 return [] 105 106 def viewitems(self): # real signature unknown; restored from __doc__ 107 """ 所有项，只是将内容保存至view对象中 """ 108 """ D.viewitems() -> a set-like object providing a view on D's items """ 109 pass 110 111 def viewkeys(self): # real signature unknown; restored from __doc__ 112 """ D.viewkeys() -> a set-like object providing a view on D's keys """ 113 pass 114 115 def viewvalues(self): # real signature unknown; restored from __doc__ 116 """ D.viewvalues() -> an object providing a view on D's values """ 117 pass 118 119 def __cmp__(self, y): # real signature unknown; restored from __doc__ 120 """ x.__cmp__(y) <==> cmp(x,y) """ 121 pass 122 123 def __contains__(self, k): # real signature unknown; restored from __doc__ 124 """ D.__contains__(k) -> True if D has a key k, else False """ 125 return False 126 127 def __delitem__(self, y): # real signature unknown; restored from __doc__ 128 """ x.__delitem__(y) <==> del x[y] """ 129 pass 130 131 def __eq__(self, y): # real signature unknown; restored from __doc__ 132 """ x.__eq__(y) <==> x==y """ 133 pass 134 135 def __getattribute__(self, name): # real signature unknown; restored from __doc__ 136 """ x.__getattribute__('name') <==> x.name """ 137 pass 138 139 def __getitem__(self, y): # real signature unknown; restored from __doc__ 140 """ x.__getitem__(y) <==> x[y] """ 141 pass 142 143 def __ge__(self, y): # real signature unknown; restored from __doc__ 144 """ x.__ge__(y) <==> x>=y """ 145 pass 146 147 def __gt__(self, y): # real signature unknown; restored from __doc__ 148 """ x.__gt__(y) <==> x>y """ 149 pass 150 151 def __init__(self, seq=None, **kwargs): # known special case of dict.__init__ 152 """ 153 dict() -> new empty dictionary 154 dict(mapping) -> new dictionary initialized from a mapping object's 155 (key, value) pairs 156 dict(iterable) -> new dictionary initialized as if via: 157 d = {} 158 for k, v in iterable: 159 d[k] = v 160 dict(**kwargs) -> new dictionary initialized with the name=value pairs 161 in the keyword argument list. For example: dict(one=1, two=2) 162 # (copied from class doc) 163 """ 164 pass 165 166 def __iter__(self): # real signature unknown; restored from __doc__ 167 """ x.__iter__() <==> iter(x) """ 168 pass 169 170 def __len__(self): # real signature unknown; restored from __doc__ 171 """ x.__len__() <==> len(x) """ 172 pass 173 174 def __le__(self, y): # real signature unknown; restored from __doc__ 175 """ x.__le__(y) <==> x<=y """ 176 pass 177 178 def __lt__(self, y): # real signature unknown; restored from __doc__ 179 """ x.__lt__(y) <==> x<y """ 180 pass 181 182 @staticmethod # known case of __new__ 183 def __new__(S, *more): # real signature unknown; restored from __doc__ 184 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 185 pass 186 187 def __ne__(self, y): # real signature unknown; restored from __doc__ 188 """ x.__ne__(y) <==> x!=y """ 189 pass 190 191 def __repr__(self): # real signature unknown; restored from __doc__ 192 """ x.__repr__() <==> repr(x) """ 193 pass 194 195 def __setitem__(self, i, y): # real signature unknown; restored from __doc__ 196 """ x.__setitem__(i, y) <==> x[i]=y """ 197 pass 198 199 def __sizeof__(self): # real signature unknown; restored from __doc__ 200 """ D.__sizeof__() -> size of D in memory, in bytes """ 201 pass 202 203 __hash__ = None 204 205 dict
具体用法：
id_db={ 123:{ "name":"tianjie", "age":12, "job":"IT", }, 345:{ "name":"xiaobai", "age":13, "job":"IT", }, } # id_db[123]["name"]="xiaohei" #修改 # print(id_db) # id_db[345]["xingbie"]="nan" #添加 # print(id_db) # id_db[123].pop("age") #删除 # # del id_db[123]["name"] # # print(id_db) # #d=id_db.get(123) #取值 没有值，也不报错 # d=id_db.get(456) # print(d) # dic2={ # "name":"xiaoma", # "age":18, # "job":"IT", # } # id_db.update(dic2) #覆盖，有就覆盖，不存在添加新的 # print(id_db) # print(id_db.keys()) #取key # print(id_db.values())#取元素 print(dict.fromkeys([1,2,3,4],'ddd'))#把后面的ddd做元素分别赋值给前面的列表生成字典（据说里面有坑）
dic1 = {
'alex':'good',
'wuSIR':'good',
'wb':'DSB'
}
for i in dic1:
print(i)
#循环取得是key
#输出结果为：
alex
wuSIR
wb
print(len(dic1)) #计算字典元素个数，即键的总数
print(str(dic1)) #输出字典以可打印的字符串表示
print(type(dic1)) #返回输入的变量类型，如果变量是字典就返回字典类型
练习：
练习：元素分类 有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，将所有大于 66 的值保存至字典的第一个key中，将小于 66 的值保存至第二个key的值中。 即： {'k1': 大于66 , 'k2': 小于66}
1 li=[11,22,33,44,55,66,77,88,99] 2 dic={} 3 for i in li: 4 if i>66: 5 if "k1" in dic.keys(): 6 dic["k1"].append(i) 7 else: 8 dic["k1"]=[i,] 9 else: 10 if "k2" in dic.keys(): 11 dic["k2"].append(i) 12 else: 13 dic["k2"] =[i,] 14 print(dic)
1 num=[11,22,33,44,55,66,77,88,99] 2 name=collections.defaultdict(list) #指定了默认字典 3 for i in num: 4 if i >66: 5 name["k1"].append(i) 6 else: 7 name["k2"].append(i) 8 print(name)
7、set集合：
首先说set的是什么？
set是一个无序的，不可重复的元组集合，也可嵌套。
创建集合：
se={1,2,3,4}
se=set(1,2,3,4)
se=set([1,2,3,4,"q","a"])
集合都有哪些功能：
1 class set(object): 2 """ 3 set() -> new empty set object 4 set(iterable) -> new set object 5 6 Build an unordered collection of unique elements. 7 """ 8 def add(self, *args, **kwargs): # real signature unknown 9 """ 10 Add an element to a set，添加元素 11 12 This has no effect if the element is already present. 13 """ 14 pass 15 16 def clear(self, *args, **kwargs): # real signature unknown 17 """ Remove all elements from this set. 清除内容""" 18 pass 19 20 def copy(self, *args, **kwargs): # real signature unknown 21 """ Return a shallow copy of a set. 浅拷贝 """ 22 pass 23 24 def difference(self, *args, **kwargs): # real signature unknown 25 """ 26 Return the difference of two or more sets as a new set. A中存在，B中不存在 27 28 (i.e. all elements that are in this set but not the others.) 29 """ 30 pass 31 32 def difference_update(self, *args, **kwargs): # real signature unknown 33 """ Remove all elements of another set from this set. 从当前集合中删除和B中相同的元素""" 34 pass 35 36 def discard(self, *args, **kwargs): # real signature unknown 37 """ 38 Remove an element from a set if it is a member. 39 40 If the element is not a member, do nothing. 移除指定元素，不存在不保错 41 """ 42 pass 43 44 def intersection(self, *args, **kwargs): # real signature unknown 45 """ 46 Return the intersection of two sets as a new set. 交集 47 48 (i.e. all elements that are in both sets.) 49 """ 50 pass 51 52 def intersection_update(self, *args, **kwargs): # real signature unknown 53 """ Update a set with the intersection of itself and another. 取交集并更更新到A中 """ 54 pass 55 56 def isdisjoint(self, *args, **kwargs): # real signature unknown 57 """ Return True if two sets have a null intersection. 如果没有交集，返回True，否则返回False""" 58 pass 59 60 def issubset(self, *args, **kwargs): # real signature unknown 61 """ Report whether another set contains this set. 是否是子序列""" 62 pass 63 64 def issuperset(self, *args, **kwargs): # real signature unknown 65 """ Report whether this set contains another set. 是否是父序列""" 66 pass 67 68 def pop(self, *args, **kwargs): # real signature unknown 69 """ 70 Remove and return an arbitrary set element. 71 Raises KeyError if the set is empty. 移除元素 72 """ 73 pass 74 75 def remove(self, *args, **kwargs): # real signature unknown 76 """ 77 Remove an element from a set; it must be a member. 78 79 If the element is not a member, raise a KeyError. 移除指定元素，不存在保错 80 """ 81 pass 82 83 def symmetric_difference(self, *args, **kwargs): # real signature unknown 84 """ 85 Return the symmetric difference of two sets as a new set. 对称差集 86 87 (i.e. all elements that are in exactly one of the sets.) 88 """ 89 pass 90 91 def symmetric_difference_update(self, *args, **kwargs): # real signature unknown 92 """ Update a set with the symmetric difference of itself and another. 对称差集，并更新到a中 """ 93 pass 94 95 def union(self, *args, **kwargs): # real signature unknown 96 """ 97 Return the union of sets as a new set. 并集 98 99 (i.e. all elements that are in either set.) 100 """ 101 pass 102 103 def update(self, *args, **kwargs): # real signature unknown 104 """ Update a set with the union of itself and others. 更新 """ 105 pass
具体用法：
1 name=set() #定义集合 2 name.add("tianjie") #添加集合 3 print(name) 4 name.update(["k1","a1","a2","a3"])#更新 5 print(name) 6 7 name1=set(["k2","k3","k4","a1"]) 8 print(name1) 9 name2=name1.difference(name) #取变量name1中，name变量中不存在的元素生成一个新的set 10 print(name2) 11 12 name3=set(["v1","v2","v3","v4"]) 13 print(name3) 14 15 name4=name3.intersection(["v1","d1","v0","v2"])#取交集生成新的set or name4=name3.intersection(name1) 里面也可以是另一个集合变量 16 print(name4) 17 18 name3.intersection_update(name4)#取交集修改原来的set 就是把原来name3替换成交集的结果 19 print(name3) 20 21 print(name3.isdisjoint(name4)) #如果name3和name4是否有交集 没有则返回True 有就返回False 22 print(name3.issuperset(name4))#是name3是否是name4父集,是就为True ，就是name3是否包含name4 23 name4=name3.pop() #移除一个元素，获取到移除的元素,注意这是随机的 24 print(name3) 25 print(name4) 26 27 name3.remove("v2") #移除指定元素，没有就报错 28 print(name3) 29 30 name3.discard("v2") #移除指定元素，没有也不报错
实例练习：
寻找差异：
# 数据库中原有 old_dict = { "#1":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 }, "#2":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 } "#3":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 } } # cmdb 新汇报的数据 new_dict = { "#1":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 800 }, "#3":{ 'hostname':c1, 'cpu_count': 2, 'mem_capicity': 80 } "#4":{ 'hostname':c2, 'cpu_count': 2, 'mem_capicity': 80 } }
列出需要删除，需要添加，需要更新的项，
无需考虑内部元素是否改变，只要原来存在，新汇报也存在，就是需要更新
1 需要添加的项： 2 就是新的有（new_dict）,旧的没有的项（old_dict）添加 3 代码： 4 A=set(old_dict) 5 B=set(new_dict) 6 s1=B.difference(A) 7 需要删除的项： 8 就是旧的有，新的没有 删除 9 代码： 10 s2=A.difference(B) 11 需要更新的项： 12 就是旧的有，新的也有 就是需要更新的 13 s3=A.intersection(B)
集合简写（特殊字符代替）：
1 name1=set(["v1","v2","v3","v4"]) 2 print(name1) 3 name2=set(["v1","v2","a","a1","v6"]) 4 print(name2) 5 print(name1&name2) #交集 6 print(name1|name2) #并集 7 print(name1-name2)#差集显示name1差集，name1有name2没有 8 print(name2-name1)#差集显示name2差集，name2有name1没有 9 print(name1^name2)#求对称差集，name1没有name2的，name2中的没有name1的
以上输出结果：
1 C:PythonPython35python.exe D:/学习功课/s13/day3/set集合.py 2 {'v1', 'v2', 'v4', 'v3'} 3 {'a1', 'v1', 'a', 'v2', 'v6'} 4 {'v1', 'v2'} 5 {'v4', 'v2', 'v6', 'a1', 'v1', 'v3', 'a'} 6 {'v4', 'v3'} 7 {'a1', 'a', 'v6'} 8 {'v4', 'v6', 'a1', 'v3', 'a'} 9 10 Process finished with exit code 0