python常用的字符串操作

记录python中字符串的操作，以后有了其他的操作会在这个文件中追加

  if __name__ == "__main__":
      str1 = "Yuang"
      str2 = "PangZi"
      str3 = "YuangPangZi"
      str_list = [str1, str2, str3]
      StrAdd(str1, str2)
      StrSub(str3, str1)
      StrAddList(str_list)
      LoopRead(str1)
      StrSplit(str3)
      FindStr(str3, str1)
      FindStr2(str3, str1)

字符串相加

def StrAdd(str1:str, str2:str):  #指定参数的数据类型
    res = str1 + str2
    print("StrAdd: ",res)
    return res

StrAdd:  YuangPangZi

N个字符串相加

def StrAddList(*args):
res = ""
for s in args[0]:
    if isinstance(s, str):
        res += s
print("StrAddList: ", res)
return res

StrAddList:  YuangPangZiYuangPangZi

字符串替换

def StrSub(source:str, str1:str): 
    res = source.replace(str1, "") #说是减法实则替换
    print("StrSub: ", res)
    return res

StrSub:  PangZi

循环读取字符串

def LoopRead(source:str):
    for i in source:
        print("Loop Str: ", i)

Loop Str:  Y
Loop Str:  u
Loop Str:  a
Loop Str:  n
Loop Str:  g

字符串截取

def StrSplit(source:str):
    print("get one char:", source[0], source[1]) #取字符串指定内容1：
    print("get sting in range:",  source[0:2]) #左闭右开 取字符串的指定范围
    print("get char in range for behand:", source[-3: -1]) #从后往前数截取
    print("get one char:", source[-1], source[-2])

get one char: Y u
get sting in range: Yu
get char in range for behand: gZ
get one char: i Z

字符串查找

#在source中查找tag是否存在
def FindStr(source:str, tag:str):
    if tag in source:
        print("True")
        return True
    else:
        print("False")
        return False

True

import re
#在source中查找tag并获取数量
def FindStr2(source:str, tag:str):
    res = re.findall(tag, source)
    print("res:", res)
    print("res len", len(res))