Python String `startswith()` Method

The Python string startswith() method checks whether a string begins with specific text.

It is useful when you want a simple True or False answer. Beginners often use it to test commands, filenames, labels, and other text patterns.

text = "Python Beginner Help"

print(text.startswith("Python"))   # True
print(text.startswith("Beginner")) # False

Use startswith() when you want to check whether a string begins with certain text.

What `startswith()` does

startswith() is a string method that checks the beginning of a string.

It checks whether a string begins with a given value
It returns True or False
It does not change the original string
It works only on strings

Example:

name = "Python"

print(name.startswith("Py"))   # True
print(name.startswith("py"))   # False

Basic syntax

The main form is:

string.startswith(prefix)

You can also use:

string.startswith(prefix, start)
string.startswith(prefix, start, end)

Here, prefix is the text you want to check at the beginning.

Example:

text = "hello world"

print(text.startswith("hello"))      # True
print(text.startswith("world"))      # False
print(text.startswith("world", 6))   # True

If you are new to Python strings, see Python strings explained: basics and examples.

Parameters explained

startswith() can take up to three arguments.

`prefix`

This is the starting text you want to match.

text = "banana"
print(text.startswith("ban"))  # True

`start`

This optional number tells Python where to begin checking.

text = "hello world"
print(text.startswith("world", 6))  # True

`end`

This optional number tells Python where to stop checking.

text = "hello world"
print(text.startswith("wor", 6, 9))  # True

Multiple prefixes

prefix can also be a tuple of strings. This lets you test more than one possible beginning.

filename = "img_001.png"
print(filename.startswith(("img_", "photo_")))  # True

Return value

startswith() always returns a Boolean value:

True if the string starts with the prefix
False if it does not

This makes it useful in if statements.

command = "/help"

if command.startswith("/"):
    print("This looks like a command.")
else:
    print("This is normal text.")

Output:

This looks like a command.

Using `startswith()` with `start` and `end`

The start and end arguments let you check part of a string without slicing it yourself.

start lets you begin checking from a later position
end limits the part of the string being checked
This is useful when working with substrings

Example:

text = "one two three"

print(text.startswith("two", 4))        # True
print(text.startswith("three", 8, 13))  # True
print(text.startswith("three", 8, 12))  # False

In the last example, the end position stops too early, so the full prefix cannot match.

Using multiple prefixes

If more than one prefix is allowed, pass a tuple.

This is cleaner than writing several or conditions.

filename1 = "img_101.jpg"
filename2 = "photo_202.jpg"
filename3 = "doc_303.jpg"

allowed = ("img_", "photo_")

print(filename1.startswith(allowed))  # True
print(filename2.startswith(allowed))  # True
print(filename3.startswith(allowed))  # False

This is especially helpful when checking file naming rules.

You may also want to compare this with the Python string endswith() method if you need to check the end of a string instead.

Case sensitivity

startswith() is case-sensitive.

That means "Python" and "python" are different.

text = "Python"

print(text.startswith("Py"))  # True
print(text.startswith("py"))  # False

If you want a case-insensitive check, convert the string first with lower().

text = "Python"

print(text.lower().startswith("py"))  # True

When to use `startswith()`

startswith() is useful in many real programs.

Common uses include:

Checking filename patterns at the start
Checking user input prefixes such as commands
Validating text formats like http:// or https://
Making code easier to read than manual slicing

Example:

url = "https://example.com"

if url.startswith(("http://", "https://")):
    print("This looks like a web URL.")

Common mistakes

Here are some common beginner mistakes when using startswith().

Using the wrong letter case

startswith() is case-sensitive.

text = "Python"
print(text.startswith("python"))  # False

Fix:

print(text.lower().startswith("python"))  # True

Calling `startswith()` on a non-string value

This method works on strings, not numbers or lists.

value = 123

# This will cause an error:
# print(value.startswith("1"))

Fix:

value = str(123)
print(value.startswith("1"))  # True

Confusing `startswith()` with `in`

startswith() checks only the beginning.

If you want to know whether text appears anywhere, use in or methods like find().

text = "hello world"

print(text.startswith("world"))  # False
print("world" in text)           # True

For a task-focused guide, see how to check if a string contains a substring in Python.

Forgetting that `start` and `end` use index positions

Python counts string positions starting at 0.

text = "abcdef"

print(text.startswith("cd", 2))  # True

Passing a list instead of a tuple

Multiple prefixes must be given as a tuple, not a list.

Wrong:

# text.startswith(["Py", "Ja"])

Correct:

text = "Python"
print(text.startswith(("Py", "Ja")))  # True

Useful debugging checks:

print(text)
print(type(text))
print(text.startswith("Py"))
print(text.lower().startswith("py"))
print(text.startswith(("Py", "Ja")))

FAQ

Does `startswith()` change the string?

No. It only checks the string and returns True or False.

Can `startswith()` check more than one prefix?

Yes. Pass a tuple of strings, such as:

text.startswith(("a", "b"))

Is `startswith()` case-sensitive?

Yes. Uppercase and lowercase letters are treated as different.

What is the difference between `startswith()` and `in`?

startswith() checks only the beginning. in checks whether text appears anywhere in the string.

Can I use `start` and `end` with `startswith()`?

Yes. They let you limit which part of the string is checked.

Python String startswith() Method

Python String `startswith()` Method