在 Python 中用单个空格替换多个空格

用一个空格替换多个空格：

使用该str.split()方法在每个空白字符上拆分字符串。
使用该str.join()方法用空格连接字符串列表。
新字符串中的单词将由一个空格分隔。

主程序


my_str = 'bobby   hadz  com'

# ✅ replace multiple whitespace characters with single space

result = " ".join(my_str.split())
print(repr(result))  # 👉️ 'bobby hadz com'

该示例使用str.split()和str.join()方法将多个空白字符替换为一个空格。

str.split ()方法使用定界符将字符串拆分为子字符串列表。

当在没有分隔符的情况下调用该str.split()方法时，它将连续的空白字符视为单个分隔符。

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my_str = 'bobby   hadz  com'

# 👇️ ['bobby', 'hadz', 'com']
print(my_str.split())

当不带参数调用时，该str.split()方法将拆分为连续的空白字符（例如\t,\n等），而不仅仅是空格。

下一步是使用该str.join()方法连接带有空格分隔符的字符串列表。

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my_str = 'bobby   hadz  com'

result = " ".join(my_str.split())
print(repr(result))  # 👉️ 'bobby hadz com'

# 👇️ bobby hadz com
print(' '.join(['bobby', 'hadz', 'com']))

str.join方法将一个可迭代对象作为参数并返回一个字符串，该字符串是可迭代对象中字符串的串联。

调用该方法的字符串用作元素之间的分隔符。

使用单个空格替换多个空格`re.sub()`

另一种方法是使用re.sub()方法。

该re.sub方法将返回一个新字符串，该字符串是通过将所有出现的多个空格替换为一个空格而获得的。

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import re

my_str = 'bobby   hadz  com'

# 👇️ only covers spaces
result = re.sub(' +', ' ', my_str)
print(repr(result))  # 👉️ 'bobby hadz com'

如果您需要用一个空格替换多个空白字符，请改用以下代码示例。

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import re

my_str = 'bobby   hadz  com'

# 👇️ covers spaces, tabs and newline chars
result = re.sub(r'\s+', ' ', my_str)
print(repr(result))  # 👉️ 'bobby hadz com'

re.sub方法返回一个新字符串，该字符串是通过用提供的替换替换模式的出现而获得的。

如果未找到模式，则按原样返回字符串。

我们传递给该方法的第一个参数re.sub是一个正则表达式。

在我们的正则表达式中，我们有一个空格和一个加号+。

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result = re.sub(' +', ' ', my_str)

加号+用于匹配前面的字符（空格）1 次或多次。

In its entirety, the example replaces 1 or more consecutive spaces with a single
space.

Note that the re.sub() method returns a new string, it doesn’t mutate the
original string as strings are immutable in Python.

If you need to replace all whitespace characters with a single space, use the
\s special character instead.

main.py


import re

my_str = 'bobby   hadz  com'

result = re.sub(r'\s+', ' ', my_str)
print(repr(result))  # 👉️ 'bobby hadz com'

The \s character matches Unicode whitespace characters like [ \t\n\r\f\v].

If your string has trailing whitespace, you might have to use the str.strip()
method to remove it before calling re.sub().

main.py


import re

my_str = 'bobby   hadz  com  '

result = re.sub(r'\s+', ' ', my_str.strip())
print(repr(result))  # 👉️ 'bobby hadz com'

The str.strip method returns a copy of
the string with the leading and trailing whitespace removed.

# Replace multiple spaces with a single space in a file in Python

To replace multiple spaces with a single space in a file:

Open the first file in reading mode.
Open the second file in writing mode.
Use the split() and join() methods to replace multiple spaces with a
single space.

main.py


with open('file-1.txt', 'r', encoding='utf-8') as old_file:
    lines = old_file.readlines()

    with open('file-2.txt', 'w', encoding='utf-8') as new_file:
        for line in lines:
            new_file.write(' '.join(line.split()) + '\n')

The code sample assumes that you have a file named file-1.txt located in the
same directory as your Python script.

file-1.txt


bobby    hadz   com
one      two    three

We opened the first file in r (reading) mode and read its lines.

Then, we opened the second file in w (writing) mode and used a
for loop to iterate over the lines of the
first file.

On each iteration, we replace multiple spaces with a single space and write the
result to the second file.

The contents of file-2.txt look as follows.

file-2.txt


bobby hadz com
one two three

# Additional Resources

您可以通过查看以下教程来了解有关相关主题的更多信息：

在 Python 中用单个空格替换多个空格

目录

Replace multiple spaces with a single space in Python