How to delete a line from a text file using the line number in python

Question

here is an example text file

the bird flew
the dog barked
the cat meowed

here is my code to find the line number of the phrase i want to delete

phrase = 'the dog barked'

with open(filename) as myFile:
    for num, line in enumerate(myFile, 1):
        if phrase in line:
            print 'found at line:', num

what can i add to this to be able to delete the line number (num) i have tried

lines = myFile.readlines()
del line[num]

but this doesnt work how should i approach this?

Answer 1

You could use the fileinput module to update the file - note this will remove all lines containing the phrase:

import fileinput

for line in fileinput.input(filename, inplace=True):
    if phrase in line:
        continue
    print(line, end='')