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  • Python开发【第三篇】:Python基本数据类型

    运算符

    1、算数运算

    2、比较运算:

    3、赋值运算:

    4、逻辑运算:

    5、成员运算:

    基本数据类型

    1、数字

    int(整型)

      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
    2、布尔值
      真或假
      1 或 0
    3、字符串
    "hello world"
    字符串常用功能:
    • 移除空白
    • 分割
    • 长度
    • 索引
    • 切片
    • class str(basestring):
          """
          str(object='') -> string
          
          Return a nice string representation of the object.
          If the argument is a string, the return value is the same object.
          """
          def capitalize(self):  
              """ 首字母变大写 """
              """
              S.capitalize() -> string
              
              Return a copy of the string S with only its first character
              capitalized.
              """
              return ""
      
          def center(self, width, fillchar=None):  
              """ 内容居中,width:总长度;fillchar:空白处填充内容,默认无 """
              """
              S.center(width[, fillchar]) -> string
              
              Return S centered in a string of length width. Padding is
              done using the specified fill character (default is a space)
              """
              return ""
      
          def count(self, sub, start=None, end=None):  
              """ 子序列个数 """
              """
              S.count(sub[, start[, end]]) -> int
              
              Return the number of non-overlapping occurrences of substring sub in
              string S[start:end].  Optional arguments start and end are interpreted
              as in slice notation.
              """
              return 0
      
          def decode(self, encoding=None, errors=None):  
              """ 解码 """
              """
              S.decode([encoding[,errors]]) -> object
              
              Decodes S using the codec registered for encoding. encoding defaults
              to the default encoding. errors may be given to set a different error
              handling scheme. Default is 'strict' meaning that encoding errors raise
              a UnicodeDecodeError. Other possible values are 'ignore' and 'replace'
              as well as any other name registered with codecs.register_error that is
              able to handle UnicodeDecodeErrors.
              """
              return object()
      
          def encode(self, encoding=None, errors=None):  
              """ 编码,针对unicode """
              """
              S.encode([encoding[,errors]]) -> object
              
              Encodes S using the codec registered for encoding. encoding defaults
              to the default encoding. errors may be given to set a different error
              handling scheme. Default is 'strict' meaning that encoding errors raise
              a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and
              'xmlcharrefreplace' as well as any other name registered with
              codecs.register_error that is able to handle UnicodeEncodeErrors.
              """
              return object()
      
          def endswith(self, suffix, start=None, end=None):  
              """ 是否以 xxx 结束 """
              """
              S.endswith(suffix[, start[, end]]) -> bool
              
              Return True if S ends with the specified suffix, False otherwise.
              With optional start, test S beginning at that position.
              With optional end, stop comparing S at that position.
              suffix can also be a tuple of strings to try.
              """
              return False
      
          def expandtabs(self, tabsize=None):  
              """ 将tab转换成空格,默认一个tab转换成8个空格 """
              """
              S.expandtabs([tabsize]) -> string
              
              Return a copy of S where all tab characters are expanded using spaces.
              If tabsize is not given, a tab size of 8 characters is assumed.
              """
              return ""
      
          def find(self, sub, start=None, end=None):  
              """ 寻找子序列位置,如果没找到,返回 -1 """
              """
              S.find(sub [,start [,end]]) -> int
              
              Return the lowest index in S where substring sub is found,
              such that sub is contained within S[start:end].  Optional
              arguments start and end are interpreted as in slice notation.
              
              Return -1 on failure.
              """
              return 0
      
          def format(*args, **kwargs): # known special case of str.format
              """ 字符串格式化,动态参数,将函数式编程时细说 """
              """
              S.format(*args, **kwargs) -> string
              
              Return a formatted version of S, using substitutions from args and kwargs.
              The substitutions are identified by braces ('{' and '}').
              """
              pass
      
          def index(self, sub, start=None, end=None):  
              """ 子序列位置,如果没找到,报错 """
              S.index(sub [,start [,end]]) -> int
              
              Like S.find() but raise ValueError when the substring is not found.
              """
              return 0
      
          def isalnum(self):  
              """ 是否是字母和数字 """
              """
              S.isalnum() -> bool
              
              Return True if all characters in S are alphanumeric
              and there is at least one character in S, False otherwise.
              """
              return False
      
          def isalpha(self):  
              """ 是否是字母 """
              """
              S.isalpha() -> bool
              
              Return True if all characters in S are alphabetic
              and there is at least one character in S, False otherwise.
              """
              return False
      
          def isdigit(self):  
              """ 是否是数字 """
              """
              S.isdigit() -> bool
              
              Return True if all characters in S are digits
              and there is at least one character in S, False otherwise.
              """
              return False
      
          def islower(self):  
              """ 是否小写 """
              """
              S.islower() -> bool
              
              Return True if all cased characters in S are lowercase and there is
              at least one cased character in S, False otherwise.
              """
              return False
      
          def isspace(self):  
              """
              S.isspace() -> bool
              
              Return True if all characters in S are whitespace
              and there is at least one character in S, False otherwise.
              """
              return False
      
          def istitle(self):  
              """
              S.istitle() -> bool
              
              Return True if S is a titlecased string and there is at least one
              character in S, i.e. uppercase characters may only follow uncased
              characters and lowercase characters only cased ones. Return False
              otherwise.
              """
              return False
      
          def isupper(self):  
              """
              S.isupper() -> bool
              
              Return True if all cased characters in S are uppercaseand there is
              at least one cased character in S, False otherwise.
              """
              return False
      
          def join(self, iterable):  
              """ 连接 """
              """
              S.join(iterable) -> string
              
              Return a string which is the concatenation of the strings in the
              iterable.  The separator between elements is S.
              """
              return ""
      
          def ljust(self, width, fillchar=None):  
              """ 内容左对齐,右侧填充 """
              """
              S.ljust(width[, fillchar]) -> string
              
              Return S left-justified in a string of length width. Padding is
              done using the specified fill character (default is a space).
              """
              return ""
      
          def lower(self):  
              """ 变小写 """
              """
              S.lower() -> string
              
              Return a copy of the string S converted to lowercase.
              """
              return ""
      
          def lstrip(self, chars=None):  
              """ 移除左侧空白 """
              """
              S.lstrip([chars]) -> string or unicode
              
              Return a copy of the string S with leading whitespace removed.
              If chars is given and not None, remove characters in chars instead.
              If chars is unicode, S will be converted to unicode before stripping
              """
              return ""
      
          def partition(self, sep):  
              """ 分割,前,中,后三部分 """
              """
              S.partition(sep) -> (head, sep, tail)
              
              Search for the separator sep in S, and return the part before it,
              the separator itself, and the part after it.  If the separator is not
              found, return S and two empty strings.
              """
              pass
      
          def replace(self, old, new, count=None):  
              """ 替换 """
              """
              S.replace(old, new[, count]) -> string
              
              Return a copy of string S with all occurrences of substring
              old replaced by new.  If the optional argument count is
              given, only the first count occurrences are replaced.
              """
              return ""
      
          def rfind(self, sub, start=None, end=None):  
              """
              S.rfind(sub [,start [,end]]) -> int
              
              Return the highest index in S where substring sub is found,
              such that sub is contained within S[start:end].  Optional
              arguments start and end are interpreted as in slice notation.
              
              Return -1 on failure.
              """
              return 0
      
          def rindex(self, sub, start=None, end=None):  
              """
              S.rindex(sub [,start [,end]]) -> int
              
              Like S.rfind() but raise ValueError when the substring is not found.
              """
              return 0
      
          def rjust(self, width, fillchar=None):  
              """
              S.rjust(width[, fillchar]) -> string
              
              Return S right-justified in a string of length width. Padding is
              done using the specified fill character (default is a space)
              """
              return ""
      
          def rpartition(self, sep):  
              """
              S.rpartition(sep) -> (head, sep, tail)
              
              Search for the separator sep in S, starting at the end of S, and return
              the part before it, the separator itself, and the part after it.  If the
              separator is not found, return two empty strings and S.
              """
              pass
      
          def rsplit(self, sep=None, maxsplit=None):  
              """
              S.rsplit([sep [,maxsplit]]) -> list of strings
              
              Return a list of the words in the string S, using sep as the
              delimiter string, starting at the end of the string and working
              to the front.  If maxsplit is given, at most maxsplit splits are
              done. If sep is not specified or is None, any whitespace string
              is a separator.
              """
              return []
      
          def rstrip(self, chars=None):  
              """
              S.rstrip([chars]) -> string or unicode
              
              Return a copy of the string S with trailing whitespace removed.
              If chars is given and not None, remove characters in chars instead.
              If chars is unicode, S will be converted to unicode before stripping
              """
              return ""
      
          def split(self, sep=None, maxsplit=None):  
              """ 分割, maxsplit最多分割几次 """
              """
              S.split([sep [,maxsplit]]) -> list of strings
              
              Return a list of the words in the string S, using sep as the
              delimiter string.  If maxsplit is given, at most maxsplit
              splits are done. If sep is not specified or is None, any
              whitespace string is a separator and empty strings are removed
              from the result.
              """
              return []
      
          def splitlines(self, keepends=False):  
              """ 根据换行分割 """
              """
              S.splitlines(keepends=False) -> list of strings
              
              Return a list of the lines in S, breaking at line boundaries.
              Line breaks are not included in the resulting list unless keepends
              is given and true.
              """
              return []
      
          def startswith(self, prefix, start=None, end=None):  
              """ 是否起始 """
              """
              S.startswith(prefix[, start[, end]]) -> bool
              
              Return True if S starts with the specified prefix, False otherwise.
              With optional start, test S beginning at that position.
              With optional end, stop comparing S at that position.
              prefix can also be a tuple of strings to try.
              """
              return False
      
          def strip(self, chars=None):  
              """ 移除两段空白 """
              """
              S.strip([chars]) -> string or unicode
              
              Return a copy of the string S with leading and trailing
              whitespace removed.
              If chars is given and not None, remove characters in chars instead.
              If chars is unicode, S will be converted to unicode before stripping
              """
              return ""
      
          def swapcase(self):  
              """ 大写变小写,小写变大写 """
              """
              S.swapcase() -> string
              
              Return a copy of the string S with uppercase characters
              converted to lowercase and vice versa.
              """
              return ""
      
          def title(self):  
              """
              S.title() -> string
              
              Return a titlecased version of S, i.e. words start with uppercase
              characters, all remaining cased characters have lowercase.
              """
              return ""
      
          def translate(self, table, deletechars=None):  
              """
              转换,需要先做一个对应表,最后一个表示删除字符集合
              intab = "aeiou"
              outtab = "12345"
              trantab = maketrans(intab, outtab)
              str = "this is string example....wow!!!"
              print str.translate(trantab, 'xm')
              """
      
              """
              S.translate(table [,deletechars]) -> string
              
              Return a copy of the string S, where all characters occurring
              in the optional argument deletechars are removed, and the
              remaining characters have been mapped through the given
              translation table, which must be a string of length 256 or None.
              If the table argument is None, no translation is applied and
              the operation simply removes the characters in deletechars.
              """
              return ""
      
          def upper(self):  
              """
              S.upper() -> string
              
              Return a copy of the string S converted to uppercase.
              """
              return ""
      
          def zfill(self, width):  
              """方法返回指定长度的字符串,原字符串右对齐,前面填充0。"""
              """
              S.zfill(width) -> string
              
              Pad a numeric string S with zeros on the left, to fill a field
              of the specified width.  The string S is never truncated.
              """
              return ""
    4、列表
    创建列表:
    1
    2
    3
    name_list = ['alex', 'seven', 'eric']
    name_list = list(['alex', 'seven', 'eric'])

    基本操作:

    • 索引
    • 切片
    • 追加
    • 删除
    • 长度
    • 切片
    • 循环
    • 包含
    • class list(object):
          """
          list() -> new empty list
          list(iterable) -> new list initialized from iterable's items
          """
          def append(self, p_object): # real signature unknown; restored from __doc__
              """ L.append(object) -- append object to end """
              pass
      
          def count(self, value): # real signature unknown; restored from __doc__
              """ L.count(value) -> integer -- return number of occurrences of value """
              return 0
      
          def extend(self, iterable): # real signature unknown; restored from __doc__
              """ L.extend(iterable) -- extend list by appending elements from the iterable """
              pass
      
          def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
              """
              L.index(value, [start, [stop]]) -> integer -- return first index of value.
              Raises ValueError if the value is not present.
              """
              return 0
      
          def insert(self, index, p_object): # real signature unknown; restored from __doc__
              """ L.insert(index, object) -- insert object before index """
              pass
      
          def pop(self, index=None): # real signature unknown; restored from __doc__
              """
              L.pop([index]) -> item -- remove and return item at index (default last).
              Raises IndexError if list is empty or index is out of range.
              """
              pass
      
          def remove(self, value): # real signature unknown; restored from __doc__
              """
              L.remove(value) -- remove first occurrence of value.
              Raises ValueError if the value is not present.
              """
              pass
      
          def reverse(self): # real signature unknown; restored from __doc__
              """ L.reverse() -- reverse *IN PLACE* """
              pass
      
          def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__
              """
              L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;
              cmp(x, y) -> -1, 0, 1
              """
              pass
    6、字典(无序)
    创建字典:
    1
    2
    3
    person = {"name": "mr.wu", 'age': 18}
    person = dict({"name": "mr.wu", 'age': 18})

    常用操作:

    • 索引
    • 新增
    • 删除
    • 键、值、键值对
    • 循环
    • 长度
    • class dict(object):
          """
          dict() -> new empty dictionary
          dict(mapping) -> new dictionary initialized from a mapping object's
              (key, value) pairs
          dict(iterable) -> new dictionary initialized as if via:
              d = {}
              for k, v in iterable:
                  d[k] = v
          dict(**kwargs) -> new dictionary initialized with the name=value pairs
              in the keyword argument list.  For example:  dict(one=1, two=2)
          """
      
          def clear(self): # real signature unknown; restored from __doc__
              """ 清除内容 """
              """ D.clear() -> None.  Remove all items from D. """
              pass
      
          def copy(self): # real signature unknown; restored from __doc__
              """ 浅拷贝 """
              """ D.copy() -> a shallow copy of D """
              pass
      
          @staticmethod # known case
          def fromkeys(S, v=None): # real signature unknown; restored from __doc__
              """
              dict.fromkeys(S[,v]) -> New dict with keys from S and values equal to v.
              v defaults to None.
              """
              pass
      
          def get(self, k, d=None): # real signature unknown; restored from __doc__
              """ 根据key获取值,d是默认值 """
              """ D.get(k[,d]) -> D[k] if k in D, else d.  d defaults to None. """
              pass
      
          def has_key(self, k): # real signature unknown; restored from __doc__
              """ 是否有key """
              """ D.has_key(k) -> True if D has a key k, else False """
              return False
      
          def items(self): # real signature unknown; restored from __doc__
              """ 所有项的列表形式 """
              """ D.items() -> list of D's (key, value) pairs, as 2-tuples """
              return []
      
          def iteritems(self): # real signature unknown; restored from __doc__
              """ 项可迭代 """
              """ D.iteritems() -> an iterator over the (key, value) items of D """
              pass
      
          def iterkeys(self): # real signature unknown; restored from __doc__
              """ key可迭代 """
              """ D.iterkeys() -> an iterator over the keys of D """
              pass
      
          def itervalues(self): # real signature unknown; restored from __doc__
              """ value可迭代 """
              """ D.itervalues() -> an iterator over the values of D """
              pass
      
          def keys(self): # real signature unknown; restored from __doc__
              """ 所有的key列表 """
              """ D.keys() -> list of D's keys """
              return []
      
          def pop(self, k, d=None): # real signature unknown; restored from __doc__
              """ 获取并在字典中移除 """
              """
              D.pop(k[,d]) -> v, remove specified key and return the corresponding value.
              If key is not found, d is returned if given, otherwise KeyError is raised
              """
              pass
      
          def popitem(self): # real signature unknown; restored from __doc__
              """ 获取并在字典中移除 """
              """
              D.popitem() -> (k, v), remove and return some (key, value) pair as a
              2-tuple; but raise KeyError if D is empty.
              """
              pass
      
          def setdefault(self, k, d=None): # real signature unknown; restored from __doc__
              """ 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 """
              """ D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """
              pass
      
          def update(self, E=None, **F): # known special case of dict.update
              """ 更新
                  {'name':'alex', 'age': 18000}
                  [('name','sbsbsb'),]
              """
              """
              D.update([E, ]**F) -> None.  Update D from dict/iterable E and F.
              If E present and has a .keys() method, does:     for k in E: D[k] = E[k]
              If E present and lacks .keys() method, does:     for (k, v) in E: D[k] = v
              In either case, this is followed by: for k in F: D[k] = F[k]
              """
              pass
      
          def values(self): # real signature unknown; restored from __doc__
              """ 所有的值 """
              """ D.values() -> list of D's values """
              return []
      
          def viewitems(self): # real signature unknown; restored from __doc__
              """ 所有项,只是将内容保存至view对象中 """
              """ D.viewitems() -> a set-like object providing a view on D's items """
              pass
      
          def viewkeys(self): # real signature unknown; restored from __doc__
              """ D.viewkeys() -> a set-like object providing a view on D's keys """
              pass
      
          def viewvalues(self): # real signature unknown; restored from __doc__
              """ D.viewvalues() -> an object providing a view on D's values """
              pass

    其他

    1、for循环
    用户按照顺序循环可迭代对象中的内容,
    PS:break、continue
    1
    2
    3
    li = [11,22,33,44]
    for item in li:
        print item
    2、enumrate
    为可迭代的对象添加序号
    1
    2
    3
    li = [11,22,33]
    for k,v in enumerate(li, 1):
        print(k,v)
    3、range和xrange
    指定范围,生成指定的数字
    1
    2
    3
    4
    5
    6
    7
    8
    print range(1, 10)
    # 结果:[1, 2, 3, 4, 5, 6, 7, 8, 9]
     
    print range(1, 10, 2)
    # 结果:[1, 3, 5, 7, 9]
     
    print range(30, 0, -2)
    # 结果:[30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2]  
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  • 原文地址:https://www.cnblogs.com/gaowenxingxing/p/8881016.html
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