[Python] How To Convert String Case

Last Updated on 2021-12-11 by Clay

Using Python to process the case conversion of strings, or the comparison of upper and lower case strings is an extraordinarily easy task. First, Python is a simple and easy-to-write programming language. Second, these commonly used capitalization conversion methods have long been built into Python's string processing.

Today, I will record the following different Python string case processing:

• Determine case
• Convert case

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Determine case

• islower(): Determine whether the string is all lowercase
• isupper(): Determine whether the string is all uppercase
• istitle(): Determine whether the string conforms to the title format (the first letter is capitalized)

a = "lower"
b = "UPPER"
c = "This Is A Title"

print(a.islower())
print(b.isupper())
print(c.istitle())

Output:

True
True
True

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Convert case

• lower(): Convert all characters in the string to lowercase letters
• upper(): Convert all characters in the string to uppercase letters
• capitalize(): Convert the first letter to uppercase and the others to lowercase
• title(): Convert the first letter of each word to uppercase, the others are lowercase

s = "there is a BIG news!"

print("lower():", s.lower())
print("upper():", s.upper())
print("capitalize():", s.capitalize())
print("title():", s.title())

Output:

lower(): there is a big news!
upper(): THERE IS A BIG NEWS!
capitalize(): There is a big news!
title(): There Is A Big News!

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References

• https://thehelloworldprogram.com/python/python-string-methods/
• https://www.geeksforgeeks.org/isupper-islower-lower-upper-python-applications/
• https://www.programiz.com/python-programming/methods/string/lower

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