find() : case sensitive search of sub string inside main string with optional start and end position

my_str="Welcome to plus2net.com"
print(my_str.find('co'))      # Output is 3
print(my_str.find('co',4))    # Output is 20 
print(my_str.find('co',4,18)) # Output is -1

my_str.find(search_string,start,end))

search_string : String to be checked inside the main string.
start: Optional , search to start from this position
end : Optional , serch to end from this position.

Check if the search string is within our main string, if found then the position of matching string is returned. If not found then -1 is returned.

Case sensitive

find() is a case sensitive search

my_str="Welcome to plus2net.com"
print(my_str.find('CO'))      # Output is -1

Case in-sensitive serch

We can use lower() to change the case of both strings to lower and then use find()

my_str="Welcome to plus2net.com".lower()
print(my_str.find('CO'.lower()))      # Output is 3

Using if - else

my_str="Welcome to plus2net.com".lower()

if my_str.find('CO'.lower())<0:
    print('It is NOT there')
else:
    print('It is  there')

Output

It is  there

Regular Expression can be used to search string

index() and find()

We can use index() method also to search and find the position but find() method returns -1 if not found but index() method raise an exception if not found.

All String methods

index() tuple Python- Tutorials

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

About the author Watch on YouTube

Connect:

Subscribe to our YouTube Channel here