Python Modify Strings

In Python, strings come with many built-in methods that allow you to modify, clean, and transform text easily. Since strings are immutable, modification always returns a new string instead of changing the original one.

Upper Case (upper())

The upper() method converts all characters in a string to uppercase.
python
text = "python"
print(text.upper())
python
name = "Code Marathi"
print(name.upper())
python
print("hello world".upper())

Lower Case (lower())

The lower() method converts all characters to lowercase.
python
text = "PYTHON"
print(text.lower())
python
name = "AWS CLOUD"
print(name.lower())
python
print("Hello Python".lower())

Remove Whitespace (strip())

The strip() method removes extra spaces from the beginning and end of a string.
python
text = "   Python   "
print(text.strip())
python
name = "   CodeMarathi"
print(name.strip())
python
print("   Hello World   ".strip())

Replace String (replace())

The replace() method replaces a part of the string with another string.
python
text = "Hello World"
print(text.replace("World", "Python"))
python
language = "Java"
print(language.replace("Java", "Python"))
python
print("I like C".replace("C", "Python"))

Split String (split())

The split() method breaks a string into a list based on a separator.
python
text = "Python is easy"
print(text.split())
python
data = "apple,banana,orange"
print(data.split(","))
python
email = "user@gmail.com"
print(email.split("@"))

Capitalize First Letter (capitalize())

The capitalize() method converts the first character to uppercase.
python
text = "python"
print(text.capitalize())
python
name = "code marathi"
print(name.capitalize())
python
print("hello world".capitalize())

Title Case (title())

The title() method converts the first letter of each word to uppercase.
python
text = "python programming language"
print(text.title())
python
course = "aws cloud fundamentals"
print(course.title())
python
print("learn python easily".title())

Remove Specific Characters (lstrip() and rstrip())

  • lstrip() removes characters from the left
  • rstrip() removes characters from the right
python
text = "###Python"
print(text.lstrip("#"))
python
text = "Python###"
print(text.rstrip("#"))
python
text = "***Hello***"
print(text.strip("*"))

Check String Content (Useful Methods)

python
text = "Python123"
print(text.isalnum())
python
text = "Python"
print(text.isalpha())
python
text = "12345"
print(text.isdigit())

String Modification Does Not Change Original String

python
text = "python"
new_text = text.upper()
print(text)
print(new_text)

Summary

  • Strings cannot be modified directly (immutable)
  • Methods return a new modified string
  • Common methods include upper(), lower(), strip(), replace()
  • Splitting and formatting strings is easy in Python
  • String methods help clean and format user input

Exercise

  • Convert your name to uppercase
  • Remove extra spaces from a string
  • Replace a word in a sentence
  • Split a sentence into words