How to Convert Lowercase to Uppercase in Python

In Python, there are several ways you can convert a string from lowercase to uppercase. Converting character cases in Python can be very handy when you are manipulating text data for data analysis or data cleaning.

A common scenario is when you are dealing with text data and you want to convert text data to a uniform case before performing text processing. So let’s dive right into how you can convert lowercase to uppercase in Python.

Using Built-in upper() Method

Python comes with a built-in upper() method for strings. The upper() method returns the string in upper case. Here’s how you can use it:

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text = 'this is some text'
text_upper = text.upper()
print(text_upper)

This will convert all the lowercase letters in the text into uppercase letters and the output will be:

'THIS IS SOME TEXT'

Using Python’s String’s translate() Method

The translate() method returns a string where some specified characters are replaced with other specified characters.

We first make use of the maketrans() function to construct the conversion table. A call to maketrans() creates a translation mapping table which can be passed to the translate() method to replace specified characters:

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text = 'this is a test'
convert = text.maketrans('abcdefghijklmnopqrstuvwxyz','ABCDEFGHIJKLMNOPQRSTUVWXYZ')
result = text.translate(convert)
print(result)  

The expected output is:

'THIS IS A TEST'

Full Python Code for Converting Lowercase to Uppercase:

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# Using built-in upper method
text = 'this is some text'
text_upper = text.upper()
print(text_upper)
 
# Using Python's String's translate() Method
text = 'this is a test'
convert = text.maketrans('abcdefghijklmnopqrstuvwxyz','ABCDEFGHIJKLMNOPQRSTUVWXYZ')
result = text.translate(convert)
print(result)

Conclusion:

Converting a string from lowercase to uppercase is a common operation in Python programming. It’s particularly useful in cases where you want to normalize your string data to a consistent format.

The built-in upper() function and the translate() methods offer different ways to achieve this in Python. Feel free to choose what option best suits your requirements.