str.startswith()

The .startswith() method checks whether a string begins with a specified substring or one of several possible prefixes. It returns a boolean value, making it useful for conditional logic in validation, parsing, and text processing.

Syntax

str.startswith(prefix[, start[, end]])

Parameters

Parameter	Type	Default	Description
prefix	str or tuple	—	The substring or tuple of substrings to check for at the start of the string
start	int	0	Starting position for the search
end	int	len(string)	Ending position for the search

Returns: bool — True if the string starts with the prefix, False otherwise.

Examples

Basic usage

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

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

Checking multiple prefixes

message = "GET /api/users HTTP/1.1"

# Check HTTP method
if message.startswith(("GET", "POST", "PUT", "DELETE")):
    print("This is an HTTP request")
# This is an HTTP request

Using start and end parameters

url = "https://example.com/page"

# Check prefix within a slice
print(url.startswith("https", 0, 5))
# True

# Check from position 8
print(url.startswith("example", 8))
# True

See Also

• str.find()
• str.rfind()
• str.count()