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Python: Find sequences of lowercase letters joined with a underscore

Python Regular Expression: Exercise-7 with Solution

Write a Python program to find sequences of lowercase letters joined with a underscore.

Sample Solution:-

Python Code:

import re
def text_match(text):
        patterns = '^[a-z]+_[a-z]+$'
        if re.search(patterns,  text):
                return 'Found a match!'
        else:
                return('Not matched!')

print(text_match("aab_cbbbc"))
print(text_match("aab_Abbbc"))
print(text_match("Aaab_abbbc"))

Sample Output:

Found a match!                                                                                                
Not matched!                                                                                                  
Not matched!

Pictorial Presentation:

Python: Regular Expression - Find sequences of lowercase letters joined with a underscore.
Python: Regular Expression - Find sequences of lowercase letters joined with a underscore.

Flowchart:

Flowchart: Regular Expression - Find sequences of lowercase letters joined with a underscore.

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Previous: Write a Python program that matches a string that has an a followed by two to three 'b'.
Next: Write a Python program to find sequences of one upper case letter followed by lower case letters.

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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