String Methods

What You'll Learn: In this guide, you'll discover various built-in methods you can use to work with strings in Python. Each method is like a tool that helps you manipulate and explore text.

1. capitalize()

Description: Converts the first character to upper case. Example:

python
txt = "hello"
print(txt.capitalize())
# Output: Hello

2. casefold()

Description: Converts string into lower case, more aggressive than lower(). Example:

python
txt = "Hello, World!"
print(txt.casefold())
# Output: hello, world!

3. center()

Description: Returns a centered string. Example:

python
txt = "hello"
print(txt.center(10))
# Output: "  hello   "

4. count()

Description: Returns the number of times a specified value occurs in a string. Example:

python
txt = "hello world"
print(txt.count("o"))
# Output: 2

5. encode()

Description: Returns an encoded version of the string. Example:

python
txt = "Hello, World!"
print(txt.encode())
# Output: b'Hello, World!'

6. endswith()

Description: Returns true if the string ends with the specified value. Example:

python
txt = "Hello, World!"
print(txt.endswith("!"))
# Output: True

7. expandtabs()

Description: Sets the tab size of the string. Example:

python
txt = "H\te\tl\tl\to"
print(txt.expandtabs(2))
# Output: H e l l o

8. find()

Description: Searches the string for a specified value and returns the position where it was found. Example:

python
txt = "Hello, World!"
print(txt.find("World"))
# Output: 7

9. format()

Description: Formats specified values in a string. Example:

python
age = 36
txt = "My name is John, I am {}"
print(txt.format(age))
# Output: My name is John, I am 36

10. format_map()

Description: Formats specified values in a string, similar to format(). Example:

python
person = {'name': 'John', 'age': 36}
txt = "My name is {name}, I am {age}".format_map(person)
print(txt)
# Output: My name is John, I am 36

11. index()

Description: Searches the string for a specified value and returns the position where it was found. Example:

python
txt = "Hello, World!"
print(txt.index("World"))
# Output: 7

12. isalnum()

Description: Returns True if all characters in the string are alphanumeric. Example:

python
txt = "Hello123"
print(txt.isalnum())
# Output: True

13. isalpha()

Description: Returns True if all characters in the string are alphabetic. Example:

python
txt = "Hello"
print(txt.isalpha())
# Output: True

14. isascii()

Description: Returns True if all characters in the string are ASCII characters. Example:

python
txt = "Hello"
print(txt.isascii())
# Output: True

15. isdecimal()

Description: Returns True if all characters in the string are decimals. Example:

python
txt = "12345"
print(txt.isdecimal())
# Output: True

16. isdigit()

Description: Returns True if all characters in the string are digits. Example:

python
txt = "12345"
print(txt.isdigit())
# Output: True

17. isidentifier()

Description: Returns True if the string is a valid identifier. Example:

python
txt = "hello"
print(txt.isidentifier())
# Output: True

18. islower()

Description: Returns True if all characters in the string are lower case. Example:

python
txt = "hello"
print(txt.islower())
# Output: True

19. isnumeric()

Description: Returns True if all characters in the string are numeric. Example:

python
txt = "12345"
print(txt.isnumeric())
# Output: True

20. isprintable()

Description: Returns True if all characters in the string are printable. Example:

python
txt = "Hello, World!"
print(txt.isprintable())
# Output: True

21. isspace()

Description: Returns True if all characters in the string are whitespaces. Example:

python
txt = "   "
print(txt.isspace())
# Output: True

22. istitle()

Description: Returns True if the string follows the rules of a title. Example:

python
txt = "Hello, World!"
print(txt.istitle())
# Output: True

23. isupper()

Description: Returns True if all characters in the string are upper case. Example:

python
txt = "HELLO"
print(txt.isupper())
# Output: True

24. join()

Description: Joins the elements of an iterable to the end of the string. Example:

python
mylist = ["John", "Doe"]
txt = " ".join(mylist)
print(txt)
# Output: John Doe

25. ljust()

Description: Returns a left justified version of the string. Example:

python
txt = "Hello"
print(txt.ljust(10))
# Output: "Hello     "

26. lower()

Description: Converts a string into lower case. Example:

python
txt = "Hello"
print(txt.lower())
# Output: hello

27. lstrip()

Description: Returns a left trim version of the string. Example:

python
txt = " Hello "
print(txt.lstrip())
# Output: "Hello "

28. maketrans()

Description: Returns a translation table to be used in translations. Example:

python
txt = "Hello, World!"
table = txt.maketrans("H", "J")
print(txt.translate(table))
# Output: Jello, World!

29. partition()

Description: Returns a tuple where the string is parted into three parts. Example:

python
txt = "Hello, World!"
print(txt.partition(","))
# Output: ('Hello', ',', ' World!')

30. replace()

Description: Returns a string where a specified value is replaced with another specified value. Example:

python
txt = "Hello, World!"
print(txt.replace("H", "J"))
# Output: Jello, World!

31. rfind()

Description: Searches the string for a specified value and returns the last position where it was found. Example:

python
txt = "Hello, World! Hello again!"
print(txt.rfind("Hello"))
# Output: 13

32. rindex()

Description: Searches the string for a specified value and returns the last position where it was found. Example:

python
txt = "Hello, World! Hello again!"
print(txt.rindex("Hello"))
# Output: 13

33. rjust()

Description: Returns a right justified version of the string. Example:

python
txt = "Hello"
print(txt.rjust(10))
# Output: "     Hello"

34. rpartition()

Description: Returns a tuple where the string is parted into three parts. Example:

python
txt = "Hello, World!"
print(txt.rpartition(","))
# Output: ('Hello', ',', ' World!')

35. rsplit()

Description: Splits the string at the specified separator, and returns a list. Example:

python
txt = "Hello, World, Welcome"
print(txt.rsplit(","))
# Output: ['Hello', ' World', ' Welcome']

36. rstrip()

Description: Returns a right trim version of the string. Example:

python
txt = " Hello "
print(txt.rstrip())
# Output: " Hello"

37. split()

Description: Splits the string at the specified separator, and returns a list. Example:

python
txt = "Hello, World!"
print(txt.split(","))
# Output: ['Hello', ' World!']

38. splitlines()

Description: Splits the string at line breaks and returns a list. Example:

python
txt = "Hello\nWorld\nWelcome"
print(txt.splitlines())
# Output: ['Hello', 'World', 'Welcome']

39. startswith()

Description: Returns true if the string starts with the specified value. Example:

python
txt = "Hello, World!"
print(txt.startswith("Hello"))
# Output: True

40. strip()

Description: Returns a trimmed version of the string. Example:

python
txt = " Hello, World! "
print(txt.strip())
# Output: "Hello, World!"

41. swapcase()

Description: Swaps cases, lower case becomes upper case and vice versa. Example:

python
txt = "Hello, World!"
print(txt.swapcase())
# Output: hELLO, wORLD!

42. title()

Description: Converts the first character of each word to upper case. Example:

python
txt = "hello world"
print(txt.title())
# Output: Hello World

43. translate()

Description: Returns a translated string. Example:

python
txt = "Hello, World!"
table = txt.maketrans("H", "J")
print(txt.translate(table))
# Output: Jello, World!

44. upper()

Description: Converts a string into upper case. Example:

python
txt = "hello"
print(txt.upper())
# Output: HELLO

45. zfill()

Description: Fills the string with a specified number of 0 values at the beginning. Example:

python
txt = "42"
print(txt.zfill(5))
# Output: 00042
 

Try It Yourself: Fun Exercises

  1. Title Your Name:
    • Create a string with your full name.
    • Use capitalize() to format your name properly.
  2. Change the Case:
    • Write a sentence in mixed case.
    • Use lower() and upper() to change the case.
  3. Remove the Spaces:
    • Create a string with extra spaces.
    • Use strip() to clean it up.
  4. Word Swap:
    • Create a sentence.
    • Use replace() to change one word.
  5. Break It Down:
    • Write a sentence with commas.
    • Use split() to break it into a list of words.

Summary:

In this Python tutorial, we learned about various string methods you can use to manipulate and explore strings. Each method provides a unique way to handle text, making it easier to format, modify, and analyze strings. Keep experimenting and have fun with string methods in Python!