search multiple words in a string (python)-CodePudding

New learner here...

i just trying to find word in a string. can i search multiple words in one string using .find/.index or any other method?

ex = "welcome to my question. you are welcome to be here"
print(ex.find("welcome"))
result = 0

and if i try get the second word i will get -1 which mean not found

ex = "welcome to my question. you are welcome to be here"
print(ex.find("welcome", 21, 0))
result = -1

is there any other method i can use?

CodePudding user response：

You look like you were on the right track but got some of the parameters incorrect in using the find operation. Using your sample string, following is a tweaked version of the code.

ex = "welcome to my question. you are welcome to be here"

x = 0

while True:
    x = ex.find("welcome", x, len(ex))
    if x == -1:
        break
    print("welcome was found at position:", x)
    x = x   1  #Makes sure that searches are for subsequent string matches

Trying out that code resulted in the following terminal output.

@Dev:~/Python_Programs/Find$ python3 Find.py 
welcome was found at position: 0
welcome was found at position: 32

Give that a try and see if it meets the spirit of your code.

CodePudding user response：

I read this cool trick from a book "confident coding" where I learned how to do stuff like that, here you go:

# very important
import re

example = "Hello, in this string we will extract 2 numbers, number 1 and 
number 2"

result_1 = re.search("Hello, in this string we will extract 2 numbers, 
number (.*) and number (.*)", example)

# we want to print it out

print(result_1.group(1)) # prints out "1"

print(result_1.group(2)) # prints out "2"