pythonre.findall
时间: 2023-10-28 18:59:34 浏览: 102
re.findall是一个Python中的re模块的函数,用于在字符串中查找所有与正则表达式匹配的非重叠模式。
它的基本语法如下:
re.findall(pattern, string, flags=0)
其中,pattern是要匹配的正则表达式,string是要在其中查找模式的字符串,flags是可选参数,用于控制匹配的方式。
该函数返回一个包含所有匹配项的列表,如果没有匹配项则返回空列表。
例如,假设我们有一个字符串"Hello, 123456789 World!",我们想要提取其中的所有数字。可以使用re.findall来实现:
import re
text = "Hello, 123456789 World!"
numbers = re.findall('\d+', text) # 匹配一个或多个数字
print(numbers) # 输出: ['123456789']
相关问题
Python re.findall
The `re.findall()` function is a method in Python's built-in `re` module used to search for all non-overlapping occurrences of a regular expression pattern in a given string and return a list of all matched substrings.
The syntax of `re.findall()` is as follows:
```python
re.findall(pattern, string, flags=0)
```
Here, `pattern` is the regular expression pattern to search for, `string` is the input string to search in, and `flags` (optional) is an integer value that can modify the behavior of the regular expression pattern.
The `re.findall()` function returns a list containing all the matched substrings in the order they were found in the input string. If there are no matches, an empty list is returned.
Example usage:
```python
import re
text = "The quick brown fox jumps over the lazy dog"
matches = re.findall(r"\b\w{3}\b", text)
print(matches)
# Output: ['The', 'fox', 'the', 'dog']
```
In this example, the regular expression pattern `\b\w{3}\b` searches for all three-letter words in the input string `text`. The `re.findall()` function returns a list of all matched substrings, which are the words "The", "fox", "the", and "dog".
python re.findall
`re.findall` 函数是 Python 中的正则表达式库 `re` 中的一个函数,用于在字符串中查找所有与正则表达式匹配的模式,并返回一个列表,其中包含所有匹配的字符串。
用法为:`re.findall(pattern, string, flags=0)`,其中 `pattern` 为正则表达式,`string` 为要搜索的字符串,`flags` 是可选参数,用于控制正则表达式的匹配方式。
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