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Python: Remove everything except alphanumeric characters from a string

Python Regular Expression: Exercise-41 with Solution

Write a Python program to remove everything except alphanumeric characters from a string.

Sample Solution:-

Python Code:

import re
text1 = '**//Python Exercises// - 12. '
pattern = re.compile('[\W_]+')
print(pattern.sub('', text1))

Sample Output:

PythonExercises12

Pictorial Presentation:

Python: Regular Expression - Remove everything except alphanumeric characters from a string.

Flowchart:

Flowchart: Regular Expression - Remove everything except alphanumeric characters from a string.

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Python Code Editor:

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Python: Tips of the Day

Getting the last element of a list:

some_list[-1] is the shortest and most Pythonic.

In fact, you can do much more with this syntax. The some_list[-n] syntax gets the nth-to-last element. So some_list[-1] gets the last element, some_list[-2] gets the second to last, etc, all the way down to some_list[-len(some_list)], which gives you the first element.

You can also set list elements in this way. For instance:

>>> some_list = [1, 2, 3]
>>> some_list[-1] = 5 # Set the last element
>>> some_list[-2] = 3 # Set the second to last element
>>> some_list
[1, 3, 5]

Note that getting a list item by index will raise an IndexError if the expected item doesn't exist. This means that some_list[-1] will raise an exception if some_list is empty, because an empty list can't have a last element.

Ref: https://bit.ly/3d8TfFP