Python3之字符串

# Author：Allister.Liu

"""
字符串操作
"""
name = "my name is allister"
print("1:", name.capitalize()) # 首字母大写
print("2:", name.count("a")) # 统计出现的次数

print("3:", name.center(50, "-")) # 输出50个字符，不足用- 两侧填充
print(name.ljust(50, "*")) # 长度50个字符，不够用*代替，name输出在左边 left
print(name.rjust(50, "*")) # 长度50个字符，不够用*代替，name输出在右边 right

print("4:", name.endswith("er")) # 判断字符串以什么结尾
print("5:", name.find("is")) # is的索引位置
print("6:", name[0:5]) # 字符串的切片/截取

n1 = "My name is {_name}, age {_age}"
print("7:", n1.format(_name = "Allister", _age = 23)) # 格式化拼接
print("8:", n1.format_map({"_name":"Kity", "_age":25}))

print("9:", "Drdf12".isalnum(), "Drdf1#2".isalnum(), "121".isalnum(), "SfdDS".isalnum()) # 判断字符串是否是a-z or 0-9 组成
print("10:", "daQsdsa".isalpha(), "dasQdsa2".isalpha()) # 是否纯英文字符
print("11:", "312".isdigit(), "-312".isdigit(), "312.32".isdigit()) # 是否为正整数

print("12:", "name12_".isidentifier(), "3name12_".isidentifier()) # 判断是不是合法字符（合法变量名）
print("13:", "21".isnumeric(), "21.3".isnumeric(), "-21".isnumeric(), "21A".isnumeric()) # 判断是否全为数字
print("14:", " ".isspace(), "".isspace(), "c".isspace()) # 判断是否是空格

print("15:", "My Name Is Allister".istitle(), "My name is Allister".istitle(), "My Is 旺".istitle()) # 判断字符串每个词首字母是否大写，忽略中文
print("16", "dsa".isprintable()) # tyy文件或驱动文件时为False 一般用户Linux系统
print("17:", "dasdsa".islower(), "daSdsa".islower(), "DDDS".isupper(), "HDdDdd".isupper()) # 是否全为小写/大写


"""
连接字符串数组
语法：  'sep1'.join(seq2)  
参数说明: sep1：分隔符。可以为空  seq2：要连接的元素序列、字符串、元组、字典  

os.path.join()：  将多个路径组合后返回

"""
print(",".join(["1","2","3"]), "+".join(["1","2","3"]))


print("18:", "dfsaDDDsa".upper(), "DDDDdasdaSSS".lower()) # 大写变小写，小写变大写


"""
strip：去掉两边空格
lstrip：去掉左侧空格
rstrip：去掉右侧空格
"""
print("   sewqeewqd  ".strip(), "    ddasdas".lstrip(), "dfsfsdfs     ".rstrip())

"""
对应位置替换:a->q b->2 c->3 ...
"""
p = str.maketrans("abcdefg", "1234567")
print("arrays".translate(p))


print("dsSSSsss".replace("S","G"), "dsSSSsss".replace("S","G", 2)) # 替换,可以指定替换个数

print("allisteraddffg".rfind("f")) # f最右边下标

print("Allister Is A b".split(" "),"--------", "1+2+3+4+5".split("+")) # 分割，分隔符不填默认为空格

print("1+2\n+3+4+5".splitlines()) # 结果：['1+2', '+3+4+5']

print("Allister Hello".swapcase()) # 大小写互转

print("allister is fsfs".title()) # 变为title，首字母大写

print("rweDar".zfill(50)) # 方法返回指定长度的字符串，原字符串右对齐，前面填充0。

1: My name is allister
2: 2
3: ---------------my name is allister----------------
my name is allister*******************************
*******************************my name is allister
4: True
5: 8
6: my na
7: My name is Allister, age 23
8: My name is Kity, age 25
9: True False True True
10: True False
11: True False False
12: True False
13: True False False False
14: True False False
15: True False True
16 True
17: True False True False
1,2,3 1+2+3
18: DFSADDDSA dddddasdasss
sewqeewqd ddasdas dfsfsdfs
1rr1ys
dsGGGsss dsGGSsss
12
['Allister', 'Is', 'A', 'b'] -------- ['1', '2', '3', '4', '5']
['1+2', '+3+4+5']
aLLISTER hELLO
Allister Is Fsfs
00000000000000000000000000000000000000000000rweDar