Python Basics

Python String Methods

Table of Contents

Strings are a fundamental data type in Python, used to represent text or sequences of characters. They can be created using single quotes ('string'), double quotes ("string"), or raw strings with triple quotes ("python"). In this article, we will explore various methods that can be applied to string objects in Python. We will provide examples and explanations for each method to help you understand their functionality better.

[] – Accessing by Index

This is the indexing method used to access individual characters within a string. The first character has an index of 0, and indices increase from there.


custom_string = "Python Code"
print(custom_string[0]) # Output: P
print(custom_string[3]) # Output: h

len() – Determine String Length

The built-in len() function returns the length of a string, which is the number of characters it contains.


custom_string = "Python"
print(len(custom_string)) # Output: 6

replace() – String Replacement

The replace() method replaces all occurrences of a specified substring with another string.


custom_string = "Python is awesome"
new_string = custom_string.replace("Python", "Rust")
print(new_string) # Output: Rust is awesome

capitalize() – String Capitalization

The capitalize() method capitalizes the first letter of a string while keeping the rest in lowercase.


custom_string = "python rocks"
new_string = custom_string.capitalize()
print(new_string) # Output: Python rocks

upper() and lower() – Upper or Lower Case

The upper() method converts all characters in a string to uppercase, while the lower() method does the opposite by converting them to lowercase.


custom_string = "PYTHON"
print(custom_string.lower()) # Output: python
custom_string = "python"
print(custom_string.upper()) # Output: PYTHON

title() – Convert to Titles

The title() method capitalizes the first letter of each word in a string while keeping the rest lowercase.


custom_string = "python is awesome"
new_string = custom_string.title()
print(new_string) # Output: Python Is Awesome

[:] – Slicing Strings

Strings can be sliced using the same syntax as lists, allowing you to extract a portion of a string. The first and third elements in the slice are indices, while the second one is an optional step value. If no step value is provided, it defaults to 1.


custom_string = "Python"
print(custom_string[0:3]) # Output: Pyt
print(custom_string[2:]) # Output: thon
print(custom_string[:-3]) # Output: Python up to the last 3 characters

find() and rfind() – Searching and Comparing Strings

The find() method returns the index of the first occurrence of a substring within a string, while rfind() does the same but starts searching from the end (right to left). If the substring is not found, both methods return -1.


custom_string = "Python is awesome"
print(custom_string.find("is")) # Output: 7
print(custom_string.rfind("is")) # Output: 7

startswith(), endswith(), and count() – String Testing

The startswith() method checks if a string starts with the specified substring, while endswith() does the same for the end of the string. The count() method returns the number of occurrences of a substring within a string.


custom_string = "Python is awesome"
print(custom_string.startswith("Py")) # Output: True
print(custom_string.endswith("a")) # Output: False
print(custom_string.count("o")) # Output: 2

strip(), lstrip(), and rstrip() – Remove Whitespaces or specific Characters

These methods remove whitespace or specific characters from the beginning, end, or both sides of a string.


custom_string = "   Python is awesome    "
print('"' + custom_string.strip() + '"') # Output: "Python is awesome"
print('"' + custom_string.lstrip() + '"') # Output: "Python is awesome  "
print('"' + custom_string.rstrip() + '"') # Output: "  Python is awesome"

Conclusion

Python string methods provide a wide range of functionalities to manipulate and work with strings efficiently. This article has covered some essential methods, but there are many more available for you to explore. As always, remember to consult the official Python documentation for detailed information on all available methods and their usage.

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