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Python String find() Method

By IncludeHelp Last updated : December 15, 2024

Python String find() Method

The find() is an inbuilt method of python, it is used to check whether a sub-string exists in the string or not. If sub-string exists, the method returns the lowest index of the sub-string, if sub-string does not exist, method return -1.

Note: This method is case sensitive.

Syntax

String.find(sub_string[, start_index[, end_index]])

Parameters

• sub_string - a part of the string to be found in the string.
• start_index - an optional parameter, it defines the starting index from where sub_string should be found.
• end_index - an optional parameter, it defines end index of the string. Find method will find the sub_string till this end_index.

Return Value

• Returns the lowest index of the sub_string, if it exits in the string.
• Returns -1 if sub_string does not exist in the string.

Example 1

# string in which we have to find the sub_string
str = "Hello world, how are you?"

# sub_string to find the given string 
sub_str = "how"

# find by sub_str
print (str.find (sub_str))

# find by sub_str with slice:start index
print (str.find (sub_str, 10))

# find by sub_str with slice:start index and slice: end index
print (str.find (sub_str, 10, 24))

# find a sub_str that does not exist
sub_str = "friend"
# find by sub_str
print (str.find (sub_str))

# find a sub_str with different case 
sub_str = "HOW"
# find by sub_str
print (str.find (sub_str))

Output

13
13
13
-1
-1

Example 2

str1 = "Hello, welcome to the world of Python"
result1 = str1.find("welcome")
print(result1)

str2 = "Hello, Python!"
result2 = str2.find("Java")
print(result2)

str3 = "Python programming is fun"
result3 = str3.find("Python")
print(result3)

str4 = "Hello"
result4 = str4.find("o")
print(result4)

Output

7
-1
0
4