扩展后的方法说明

扩展后的replace()方法的功能：去掉字符串中的指定字符串，并返回去掉后的子字符串，替换时可设置是否区分大小写

传参说明

myString：原字符串
oldSubStr：要替换的子字符串
newSubStr：替换后的子字符串
count：要替换的次数，默认为-1（负数-全部替换，0-不替换，1-替换第1个，n-替换前n个）
caseSensitive：1-区分大小写，其他-不区分大小写

源码

 def myReplace(myString, oldSubStr, newSubStr, count=-1, caseSensitive='1'):
    # 处理传参，不合法的时候强制转换为需要的类型
    oldSubStr = str(oldSubStr)
    newSubStr = str(newSubStr)
    myString = str(myString)
    if not isinstance(count, int):
        count = -1

    # oldSubStr为空时不做替换，直接返回原字符串
    if oldSubStr == '':
        return myString

    # 区分大小写时，直接调用replace()方法处理
    if str(caseSensitive) == '1':
        myString = myString.replace(oldSubStr, newSubStr, count)
        return myString

    # 不区分大小写时，oldSubStr在myString中不存在
    # countSubString()方法见另外一篇文章：
    tem = countSubString(oldSubStr, myString, '1')
    if not tem['flag']:
        return myString

    # 不区分大小写时，oldSubStr在myString中存在
    oldSubStr = oldSubStr.lower()
    if count == 0:
        return myString
    elif count < 0:
        for i in tem['index_start']:
            myString = oldSubStr.join(myString.split(myString[i:i + len(oldSubStr)]))
    else:
        for i in tem['index_start'][:count]:
            myString = oldSubStr.join(myString.split(myString[i:i + len(oldSubStr)]))
    myString = myString.replace(oldSubStr, newSubStr, count)
    return myString  

测试结果

 # 引用
if __name__ == '__main__':
    print('结果1：', myReplace('China will be a STRONG country!', 'will', 'must',-1,'0'))
    print('结果2：', myReplace('China will be a STRONG country!', 'will', 'must',0,'0'))
    print('结果3：', myReplace('China will be a STRONG country!', 'strong', 'stronger',-1,'1'))
    print('结果4：', myReplace('China will be a STRONG country!', 'strong', 'stronger',-1,'0'))
    print('结果5：', myReplace('China will be a STRONG country!', 't', '-t-',1,'0'))
    print('结果6：', myReplace('China will be a STRONG country!', 't', '-t-',2,'0'))
    print('结果7：', myReplace('China will be a STRONG country!', '!', '',-1,'0'))
    print('结果8：', myReplace('China will be a STRONG country!', '', '',-1,'0'))
    print('结果9：', myReplace('China will be a STRONG country!', 'abc', '',-1,'0'))
    print('结果10：', myReplace('China will be a STRONG country!', ' ', '',-1,'0'))
    print('结果11：', myReplace('China will be a STRONG country!', ' ', '',2,'0'))
    print('结果12：', myReplace('China will be a STRONG country!', ' ', '',10,'0'))

# 结果
结果1： China must be a STRONG country!
结果2： China will be a STRONG country!
结果3： China will be a STRONG country!
结果4： China will be a stronger country!
结果5： China will be a S-t-RONG country!
结果6： China will be a S-t-RONG coun-t-ry!
结果7： China will be a STRONG country
结果8： China will be a STRONG country!
结果9： China will be a STRONG country!
结果10： ChinawillbeaSTRONGcountry!
结果11： Chinawillbe a STRONG country!
结果12： ChinawillbeaSTRONGcountry!