Python Program to check if String contains only Defined Characters using Regex

Python Server Side Programming Programming

When it is required to check if a given string contains specific characters using regular expression, a regular expression pattern is defined, and the string is subjected to follow this pattern.

Example

Below is a demonstration of the same

import re
def check_string(my_string, regex_pattern):

   if re.search(regex_pattern, my_string):
      print("The string contains the defined characters only")
   else:
      print("The doesnot string contain the defined characters")

regex_pattern = re.compile('^[Python]+$')

my_string_1 = 'Python'
print("The string is :")
print(my_string_1)
check_string(my_string_1 , regex_pattern)

my_string_2 = 'PythonInterpreter'
print("\nThe string is :")
print(my_string_2)
check_string(my_string_2, regex_pattern)

Output

The string is :
Python
The string contains the defined characters
The string is :
PythonInterpreter
The doesn’t string contain the defined characters

Explanation

The required packages are imported.
A method named ‘check_string’ is defined, and it takes the string and a regular expression as parameters.
The ‘search’ method is called and checked to see if a specific set of characters is present in the string.
Outside the method, the ‘compile’ method is called on the regular expression.
The string is defined and is displayed on the console.
The method is called by passing this string.
The output is displayed on the console.

AmitDiwan

Updated on: 2021-09-20T10:43:00+05:30

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