Python String find() Method

Searches the string for a given substring

Usage

The find() method searches for the first occurrence of the specified substring sub and returns its index.

If specified substring is not found, it returns -1.

The optional arguments start and end are used to limit the search to a particular portion of the string.

The find() method should be used only if you need to know the position of sub.

To check if sub is a substring or not, use the in operator:

>>> 'Py' in 'Python'
True

Syntax

string.find(sub,start,end)

Python string find() method parameters
ParameterConditionDescription
subRequiredAny string you want to search for
startOptionalAn index specifying where to start the search.
Default is 0.
endOptionalAn index specifying where to stop the search.
Default is the end of the string.

Basic Examples

Example: Find if substring ‘Developer’ contains in a string

S = 'Bob is a Developer at ABC'
x = S.find('Developer')
print(x)    # 9

find() method returns -1 if specified substring is not found in the string.

Example: Find if substring ‘Manager’ contains in a string

S = 'Bob is a Developer at ABC'
x = S.find('Manager')
print(x)    # -1

If you want to search the string from the middle, specify the start parameter.

Example: Find ‘Big’ starting a position 7

S = 'Big, Bigger, Biggest'
x = S.find('Big',7)
print(x)    # 13

You can also specify where to stop the search with end parameter.

Example: Find ‘Big’ in between 2 & 10

S = 'Big, Bigger, Biggest'
x = S.find('Big',2,10)
print(x)    # 5

find() vs index()

The find() method is identical to the index() method.

The only difference is that the index() method raises a ValueError exception, if the substring is not found.

Example:

S = 'Bob is a Developer at ABC'
x = S.find('Manager')
print(x)    # -1
# ValueError: substring not found
S = 'Bob is a Developer at ABC'
x = S.index('Manager')
print(x)