在Python中使用正则表达式提取电子邮件地址

假设您必须读取一些特定数据，例如电话号码、电子邮件地址、日期、单词集合等。您如何以非常有效的方式做到这一点？通过正则表达式做到这一点的最佳方法。

举个例子，我们必须通过正则表达式从给定的输入中只找出电子邮件。
例子：

Input  : Hello [e-mail] Rohit [e-mail]
Output : [e-mail] [e-mail]
Here we have only selected email from the given input string.

Input : My 2 favourite numbers are 7 and 10
Output :2 7 10
Here we have selected only digits.

正则表达式–
正则表达式是一个字符序列，主要用于查找和替换字符串或文件中的模式。
所以我们可以说搜索和提取任务是如此普遍，以至于Python有一个非常强大的库，称为正则表达式，可以非常优雅地处理其中的许多任务。

Symbol	Usage
$	Matches the end of the line
\s	Matches whitespace
\S	Matches any non-whitespace character
*	Repeats a character zero or more times
\S	Matches any non-whitespace character
*?	Repeats a character zero or more times (non-greedy)
+	Repeats a character one or more times
+?	Repeats a character one or more times (non-greedy)
[aeiou]	Matches a single character in the listed set
[^XYZ]	Matches a single character not in the listed set
[a-z0-9]	The set of characters can include a range
(	Indicates where string extraction is to start
)	Indicates where string extraction is to end

# Python program to extract numeric digit 
# from A string by regular expression...
  
# Importing module required for regular
# expressions
import re  
  
# Example String 
s = 'My 2 favourite numbers are 7 and 10'
  
# find all function to select all digit from 0   
# to 9 [0-9] for numeric Letter in the String
# + for repeats a character one or more times
lst = re.findall('[0-9]+', s)    
  
# Printing of List
print(lst)

输出：

['2', '7', '10']

# Python program to extract emails From 
# the String By Regular Expression. 
  
# Importing module required for regular 
# expressions 
import re 
  
# Example string 
s = """Hello from [e-mail]
        to [e-mail] about the meeting @2PM"""
  
# \S matches any non-whitespace character 
# @ for as in the Email 
# + for Repeats a character one or more times 
lst = re.findall('\S+@\S+', s)     
  
# Printing of List 
print(lst) 

输出：

['[e-mail]', '[e-mail]']

更多细节：

• Python中的正则表达式与示例|设置 1
• Python中的正则表达式 |第 2 组（搜索、匹配和查找全部）
• 正则表达式的Python文档