find() method in Python returns the index of the first occurrence of a substring within a given string. If the substring is not found, it returns -1. This method is case-sensitive, which means "abc" is treated differently from "ABC". Example:

s = "Welcome to GeekforGeeks!"
index = s.find("GeekforGeeks")
print(index)

11

Explanation: The substring "GeeksforGeeks" starts at index 11 in the string "Welcome to GeeksforGeeks!". Hence, find() method returns 11

Syntax of find() method

s.find(substring, start, end))

Parameter:

• substring: The substring to search for within the main string s.
• start (optional): The starting index from where to begin the search.
• end (optional): The ending index where the search should stop.

Return Value:

• Returns the first index of the substring if it is found within the specified range.
• Returns -1 if the substring is not found.

Examples of find() method

Example 1: We can limit the search to a specific portion of the string by providing start and end parameters.

s = "abc abc abc"
index = s.find("abc", 4)
print(index)

4

Explanation:

• The search starts from index 4, skipping the first "abc".
• The next occurrence of "abc" is found at index 8.

Example 2: The find() method is case-sensitive, so uppercase and lowercase letters are treated differently.

s = "Python is fun"
index = s.find("python")
print(index)

-1

Explanation: Since "python" (lowercase) does not match "Python" (uppercase), the method returns -1.

Example 3: In this example, we are searching for the first occurrence of a substring "abc" in a string that contains multiple spaces between the words.

s = "abc   abc   abc"
res = s.find("abc")
print(res)

0

Explanation: The substring "abc" starts at index 0 in the string "abc abc abc", so find() returns 0.

find() vs index()

Both find() and index() methods locate a substring within a string. However, they differ in behavior when the substring is not found.

• find() returns the index or -1 if not found
• index() same as find(), but raises a ValueError if not found

To learn more, please refer to "Difference Between find( ) and index( ) in Python".

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• Python | Check if substring present in string
• Python | Find position of a character in given string
• Python String Methods