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Python Strings & Methods

Q: How do I reverse a string in Python?

Use slicing with a step of -1: text[::-1]. "".join(reversed(text)) also works.

Q: How do I check if a string contains a substring?

Use in: "py" in "python" is True. Use find() when you also need the position.

Q: What is the difference between split() and split(" ")?

split() splits on any run of whitespace and ignores leading and trailing spaces. split(" ") splits on every single space, so repeated spaces give empty strings.

BeginnerLesson 16 of 4714 min read11 runnable examples

A string is a piece of text: a name, a URL, a log line, a whole file. Python strings come with dozens of built-in methods, and knowing the common ones will save you from writing loops for everyday text work.

In this lesson

Create strings with any quote style
Index and slice text
Use the most common string methods
Split text into parts and join it back

Create a string

Use single or double quotes; they mean the same thing. Pick the one that avoids escaping quotes inside the text. Triple quotes allow several lines.

Python

a = 'single quotes'b = "double quotes, with an 'apostrophe' inside"c = """Line oneLine two"""print(a)print(b)print(c)print(len(c))

Output

single quotes
double quotes, with an 'apostrophe' inside
Line one
Line two
17

A raw string, written r"...", ignores backslash escapes. It is handy for Windows paths and regular expressions:

Python

print("C:\new\table")      # \n and \t become a newline and a tabprint(r"C:\new\table")     # printed exactly as written

Output

C:
ew	able
C:\new\table

Index and slice

Strings are sequences of characters, so they support the same indexing and slicing as lists.

index	0	1	2	3	4	5
text	P	Y	T	H	O	N
negative	-6	-5	-4	-3	-2	-1

Python

text = "PYTHON"print(text[0], text[-1])print(text[0:2], text[2:], text[:-2])print(text[::2])       # every second characterprint(text[::-1])      # reversed

Output

P N
PY THON PYTH
PTO
NOHTYP

Strings are immutable

You cannot change a character in place. Methods return a new string and leave the original alone.

Python

word = "python"upper_word = word.upper()print(word, upper_word)word[0] = "P"

Output

python PYTHON
Traceback (most recent call last):
  File "main.py", line 4, in <module>
    word[0] = "P"
    ~~~~^^^
TypeError: 'str' object does not support item assignment

To “change” a string, build a new one and assign it: word = "P" + word[1:].

Change case

Python

title = "pYthon tUTORIAL"print(title.upper())print(title.lower())print(title.title())print(title.capitalize())print(title.swapcase())

Output

PYTHON TUTORIAL
python tutorial
Python Tutorial
Python tutorial
PyTHON Tutorial

Search inside a string

Python

log = "ERROR 2026-11-02 login failed for user asha"print("failed" in log)print(log.startswith("ERROR"), log.endswith(".py"))print(log.find("login"))        # index of the first matchprint(log.find("logout"))       # -1 when not foundprint(log.count("a"))

Output

True
True False
17
-1
3

Tip

find() returns -1 when the text is missing, while index() raises ValueError. Use in when you only need yes or no.

Clean up text

Python

raw = "   Pune, Maharashtra \n"print(repr(raw.strip()))print(repr(raw.lstrip()), repr(raw.rstrip()))print("--report--".strip("-"))print("2026-11-02".replace("-", "/"))print("aaa".replace("a", "b", 2))     # only the first 2

Output

'Pune, Maharashtra'
'Pune, Maharashtra \n' '   Pune, Maharashtra'
report
2026/11/02
bba

Split and join

split() breaks a string into a list. join() does the opposite: it glues a list of strings together with the string you call it on.

Python

csv_line = "asha,tester,pune"fields = csv_line.split(",")print(fields) sentence = "  learn   python   step by step "words = sentence.split()        # no argument: split on any run of whitespaceprint(words) print(" ".join(words))print("-".join(["2026", "11", "02"]))print(list("abc"))

Output

['asha', 'tester', 'pune']
['learn', 'python', 'step', 'by', 'step']
learn python step by step
2026-11-02
['a', 'b', 'c']

Check what a string contains

Python

for s in ["2026", "python", "Py3", "  ", "3.5"]:    print(repr(s).ljust(9), s.isdigit(), s.isalpha(), s.isalnum(), s.isspace())

Output

'2026'    True False True False
'python'  False True True False
'Py3'     False False True False
'  '      False False False True
'3.5'     False False False False

The columns are isdigit(), isalpha(), isalnum() and isspace(). Note that "3.5".isdigit() is False because . is not a digit.

Alignment and padding

Python

for name, score in [("Asha", 91), ("Ravi", 7), ("Meenakshi", 100)]:    print(name.ljust(10), str(score).rjust(4), str(score).zfill(5))print("menu".center(20, "*"))

Output

Asha         91 00091
Ravi          7 00007
Meenakshi   100 00100
********menu********

Common string methods

Method	Returns
`upper()`, `lower()`, `title()`	Text in a different case
`strip()`, `lstrip()`, `rstrip()`	Text without surrounding whitespace (or given characters)
`replace(old, new)`	Text with every `old` replaced
`split(sep)`	A list of parts
`sep.join(items)`	One string from a list of strings
`find(sub)` / `index(sub)`	Position of `sub` (-1 / error if missing)
`count(sub)`	How often `sub` appears
`startswith(x)` / `endswith(x)`	True or False
`isdigit()`, `isalpha()`, `isalnum()`	True or False
`ljust()`, `rjust()`, `center()`, `zfill()`	Padded text

Loop over a string

Python

word = "level"vowels = 0for ch in word:    if ch in "aeiou":        vowels += 1print("vowels:", vowels)print("palindrome:", word == word[::-1])

Output

vowels: 2
palindrome: True

Check your understanding

Predict the output

s = "Hello, World"print(s[7:], s.lower().count("l"), s.split(", "))

Quick quiz

1. What does "python"[1:4] return?

2. What does "a-b-c".split("-") return?

split() always returns a list of strings.

3. Why does name[0] = "J" fail?

Strings cannot be changed in place. Build a new one: "J" + name[1:].

4. Which returns -1 when the text is not found?

index() raises ValueError instead; count() returns 0.

Exercise: initials and username

From a full name, print the initials in upper case and a username made of the lower-case first name and the length of the full name.

Input

"  meena  ravi  kumar "

Expected output

MRK
meena16

Hint 1

split() without arguments handles the extra spaces.

Hint 2

"".join(...) can build the initials from a list.

Python

full_name = "  meena  ravi  kumar "parts = full_name.split() initials = "".join(p[0].upper() for p in parts)username = parts[0].lower() + str(len(" ".join(parts)))print(initials)print(username)

Output

MRK
meena16

split() drops all the extra spaces, giving three clean words. " ".join(parts) rebuilds the tidy name “meena ravi kumar”, whose length is 16.

Program Practice

106 Python String Programs

Every program has a step-by-step explanation, colour-coded code and its real output.

Start practising →

#1EasyFirst and last 2 characters #2EasyLength of the longest string in a list #3EasyFour copies of the last two characters #4EasyReverse a string if its length is a multiple of 4 #5EasyCount occurrences of a substring #6EasyVowel or consonant

Related sets:All practice sets

Python strings FAQ

How do I reverse a string in Python?

Use slicing with a step of -1: text[::-1]. "".join(reversed(text)) also works.

How do I check if a string contains a substring?

Use in: "py" in "python" is True. Use find() when you also need the position.

Are Python strings mutable?

No. Every method returns a new string. To change a variable, assign the new string to it: name = name.strip().

What is the difference between split() and split(” “)?

split() splits on any run of whitespace and ignores leading and trailing spaces. split(" ") splits on every single space, so repeated spaces give empty strings.