String Methods

Python provides a variety of built-in string methods that allow you to perform various operations on strings.

1. capitalize()

Converts the first character of the string to uppercase and the rest to lowercase.

text = "hello world"
capitalized_text = text.capitalize()  # 'Hello world'

2. upper() and lower()

upper(): Converts all characters in the string to uppercase.

lower(): Converts all characters in the string to lowercase.

text = "Hello World"
upper_case = text.upper()  # 'HELLO WORLD'
lower_case = text.lower()  # 'hello world'

3. title()

Converts the first character of each word to uppercase.

text = "python programming"
title_case = text.title()  # 'Python Programming'

4. len()

Returns the length (number of characters) of the string.

text = "Python"
length = len(text)  # 6

5. strip(), lstrip(), rstrip()

strip(): Removes leading and trailing whitespaces.

lstrip(): Removes leading whitespaces.

rstrip(): Removes trailing whitespaces.

spaced_text = "   Python   "
stripped_text = spaced_text.strip()   # 'Python'
left_stripped = spaced_text.lstrip()  # 'Python   '
right_stripped = spaced_text.rstrip()  # '   Python'

6. replace(old, new)

Replaces occurrences of the specified substring with another substring.

sentence = "I love programming in Python."
new_sentence = sentence.replace("Python", "JavaScript")

7. find(substring) and index(substring)

find(substring): Returns the index of the first occurrence of the substring (or -1 if not found).

index(substring): Returns the index of the first occurrence of the substring (raises an error if not found).

sentence = "Python is easy to learn."
index_of_easy = sentence.find("easy")  # 10
index_of_java = sentence.find("Java")   # -1

8. count(substring)

Returns the number of occurrences of a substring in the string.

sentence = "Python programming is fun and Python is easy to learn."
count_python = sentence.count("Python")  # 2

9. startswith(prefix) and endswith(suffix)

startswith(prefix): Returns True if the string starts with the specified prefix.

endswith(suffix): Returns True if the string ends with the specified suffix.

filename = "example.txt"
starts_with = filename.startswith("example")  # True
ends_with = filename.endswith(".txt")         # True

10. split(separator)

Splits the string into a list of substrings based on the specified separator.

sentence = "Python is easy to learn."
words = sentence.split()  # ['Python', 'is', 'easy', 'to', 'learn.']

These are just a few examples of the many string methods available in Python. Understanding and using these methods can greatly simplify string manipulation tasks in your programs.