如何在 python 3.x 中使用 string.replace()

与 2.x 中一样，使用 str.replace()。

例子：

>>> 'Hello world'.replace('world', 'Guido')
'Hello Guido'

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replace() 是 python3 中 <class 'str'> 的一个方法：

>>> 'hello, world'.replace(',', ':')
'hello: world'

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python 3 中的 replace() 方法仅用于：

a = "This is the island of istanbul"
print (a.replace("is" , "was" , 3))

#3 is the maximum replacement that can be done in the string#

>>> Thwas was the wasland of istanbul

# Last substring 'is' in istanbul is not replaced by was because maximum of 3 has already been reached

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您可以将 str.replace() 用作 str.replace() 的链。假设您有一个类似 'Testing PRI/Sec (#434242332;PP:432:133423846,335)' 的字符串，并且您想用 '-' 替换所有 '#',':',';','/' 符号。您可以通过这种方式（正常方式）替换它，

>>> string = 'Testing PRI/Sec (#434242332;PP:432:133423846,335)'
>>> string = string.replace('#', '-')
>>> string = string.replace(':', '-')
>>> string = string.replace(';', '-')
>>> string = string.replace('/', '-')
>>> string
'Testing PRI-Sec (-434242332-PP-432-133423846,335)'

或这种方式（str.replace() 链）

>>> string = 'Testing PRI/Sec (#434242332;PP:432:133423846,335)'.replace('#', '-').replace(':', '-').replace(';', '-').replace('/', '-')
>>> string
'Testing PRI-Sec (-434242332-PP-432-133423846,335)'

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尝试这个：

mystring = "This Is A String"
print(mystring.replace("String","Text"))

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Python 3 的 str.replace 的官方文档

官方文档：Python 3's str.replace

str.replace(old, new[, count]) 返回字符串的副本，其中所有出现的子字符串 old 都替换为 new。如果给定了可选参数 count，则仅替换第一个 count 出现。

对应的 VSCode 的语法说明是：

https://i.stack.imgur.com/aDYN3.png

str.replace(self: str, old, new, count) -> str

使用 str.replace 的两种方法

方法1：使用内置str的replace -> str.replace(strVariable, old, new[, count])

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

方法2：使用str变量的replace -> strVariable.replace(old, new[, count])

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

完整演示

代码：

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

截屏：

https://i.stack.imgur.com/A0f1Q.png

我的相关（中文）帖子：【详解】Python 3中字符串的替换str.replace

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仅供参考，当将一些字符附加到字符串中任意位置固定的单词（例如，通过添加后缀 -ly 将形容词更改为副词），您可以将行尾的后缀是为了便于阅读。为此，请在 replace() 中使用 split()：

s="The dog is large small"
ss=s.replace(s.split()[3],s.split()[3]+'ly')
ss
'The dog is largely small'

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简单替换： .replace(old, new, count) 。

text = "Apples taste Good."
print(text.replace('Apples', 'Bananas'))          # use .replace() on a variable
Bananas taste Good.          <---- Output

print("Have a Bad Day!".replace("Bad","Good"))    # Use .replace() on a string
Have a Good Day!             <----- Output

print("Mom is happy!".replace("Mom","Dad").replace("happy","angry"))  #Use many times
Dad is angry!                <----- Output

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ss = s.replace(s.split()[1], +s.split()[1] + 'gy')
# should have no plus after the comma --i.e.,
ss = s.replace(s.split()[1], s.split()[1] + 'gy')

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