I need to write a Python program using only find() command in files to print all those line which has Python

Question

0.00/5 (No votes)

See more:

I need do to print all that lines in which python appears using find() command in a file. Using python.

Python

fhand=open('demo.txt')                           
for line in fhand:
        line=line.rstrip()
        if(line.find('python')):
           continue
        print(line)

these are my file content

python is fun
python java 
sai python
sachin
ganesha

currently its printing first 2 lines only

What I have tried:

Python

fhand=open('demo.txt')
for line in fhand:
        line=line.rstrip()
        if(line.find('python')):
           continue
        print(line)

this is my code please help me

Posted 4-Jul-18 1:07am

Member 13898084

Updated 4-Jul-18 1:30am

Kornfeld Eliyahu Peter

v2

Add a Solution

3 solutions

Solution 3

The find method returns the index to the first occurrence of the find target. You are only printing the ones where the index is zero. Change your loop to:

Python

for line in fhand:
  line=line.rstrip()
  if(line.find('python') != -1):
    print(line)

In future please format your code properly between <pre lang="Python"></pre> tags, as I have done here. It makes it more readable.

Posted 4-Jul-18 1:30am

Richard MacCutchan

Comments

CPallini 4-Jul-18 7:47am

Wow, great minds think alike :-D
5.

Richard MacCutchan 4-Jul-18 8:14am

Yes, but you got there before me.

Solution 1

Python

if(line.find('python')):
  continue

Python String find() Method[^]
According to the documentation find() returns -1 for 'not-found' and index (0 based) for 'found'... However 'if' is about ture/false, where any number except 0 is true...

Posted 4-Jul-18 1:22am

Kornfeld Eliyahu Peter

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

CPallini · Accepted Answer · 2018-07-04T01:23:00

Solution 2

Python

fhand=open('demo.txt')
for line in fhand:
  line=line.rstrip()
  if( line.find('python') != -1):
    print(line)

Posted 4-Jul-18 1:23am

CPallini

Comments

Richard MacCutchan 4-Jul-18 8:14am

+5, now we are equal.