find and index

Learn searching with find and index.

find returns the first position of a substring; if not found, it returns -1:

"hello".find("l")   # 2
"hello".find("x")   # -1

index does the same but raises ValueError if not found. So find is safer.

Both return the index of the first match; to find later matches, use the start parameter.

Searching with find

The second parameter of find is the start position:

s = "hello"
s.find("l")        # 2
s.find("l", 3)     # 3

This is used to find the next match. With a loop you can find all match positions.

This method is very useful for searching log files.

Assign "hello world" to text. Assign text.find("world") to pos. Then print print(pos).

Show example solution

text = "hello world"
pos = text.find("world")
print(pos)

Complete the find call

pos = "hello".____("l")

Show answer

pos = "hello".find("l")