The goal is to find the line in which a word occurs in a given .txt file.
In my code I’ve defined a function and have used with open syntax.When I execute it,all i get is “enter the word you want to find” and when i enter the word,the execution automatically ends.I’ve been cracking my head as to where I went wrong,but could’nt spot my mistake.I’d be greatful if you can spot the error in the above code.

The following code in python is what I’ve tried

def find_line(x):
    f=open("practice.txt","r+")
    a=f.read()
    b=f.readlines()
    if(a.find(x)==-1):
        print("word not found!")
    else:
        line_number=1
        for line in b:
            if(line.find(x)==-1):
                line_number+=1
            else:
                print("the word exists in the line,whose number is",line_number)
x=input("enter the word you want to find")       
find_line(x)    

It stopped execution after the word input.