str.replace

Python中用来实现字符串替换的是str.replace

• 语法
  • 官网文档
    • Python 3
      • https://docs.python.org/3/library/stdtypes.html#str.replace
        • 

          str.replace(old, new[, count])

          Return a copy of the string with all occurrences of substring old replaced by new. If the optional argument count is given, only the first count occurrences are replaced

    • 对比：Python 2的官网文档，解释也基本类似：
      • https://docs.python.org/2/library/stdtypes.html#str.replace
        • 

          str.replace(old, new[, count])

          Return a copy of the string with all occurrences of substring old replaced by new. If the optional argument count is given, only the first count occurrences are replaced

对应着，VSCode中的语法提示是：

对应着，常见的，具体的用法，有2种：

• 使用方式1：直接用str的replace，即：str.replace(strVariable, old, new[, count])

    replacedStr1 = str.replace(originStr, "from", "to")
  

• 使用方式2：用字符串变量，即：strVariable.replace(old, new[, count])

    replacedStr2 = originStr.replace("from", "to")
  

完整demo代码：

# Function: Demo python 3 str.replace
# Author: Crifan Li
# Update: 20210408

originStr = "Hello world"

# Use case 1: use builtin str's replace -> str.replace(strVariable, old, new[, count])
replacedStr1 = str.replace(originStr, "world", "Crifan Li")
print("case 1: %s -> %s" % (originStr, replacedStr1))

# Use case 2: use str variable's replace -> strVariable.replace(old, new[, count])
replacedStr2 = originStr.replace("world", "Crifan Li")
print("case 2: %s -> %s" % (originStr, replacedStr2))

输出：

case 1: Hello world -> Hello Crifan Li
case 2: Hello world -> Hello Crifan Li

效果：