在本教程中,我们将编写一个程序,使用正则表达式查找字符串中所有1(0 + 1)的出现。我们在Python中有一个re模块,可以帮助我们使用正则表达式。
让我们看一个示例案例。
Input: string = "Sample 1(0+)1 string with 1(0+)1 unnecessary patterns 1(0+)1" Output: Total number of pattern maches are 3 ['1(0+)1', '1(0+)1', '1(0+)1']
请按照以下步骤编写程序代码。
1. Import the re module. 2. Initialise a string. 3. Create a regex object using regular expression which matches the pattern using the re.compile(). Remember to pass a raw string to the function instead of the usual string. 4. Now, match all the occurrence of the pattern using regex object from the above step and regex_object.findall() method. 5. The above steps return a match object and print the matched patterns using match_object.group() method.
让我们看一下代码。
# importing the re module import re # initializing the string string = "Sample 1(0+)1 string with 1(0+)1 unnecessary patterns 1(0+)1" # creating a regex object for our patter regex = re.compile(r"\d\(\d\+\)\d") # this regex object will find all the patter ns which are 1(0+)1 # storing all the matches patterns in a variable using regex.findall() method result = regex.findall(string) # result is a match object # printing the frequency of patterns print(f"Total number of pattern maches are {len(result)}") print() # printing the matches from the string using result.group() method print(result)
输出结果
如果运行上面的代码,您将获得以下输出。
Total number of pattern maches are 3 ['1(0+)1', '1(0+)1', '1(0+)1']