Question

I need some help on my code below,I have the sample input and expected output,currenlty its not printing anything..please provide your inputs,

Basically my code is parsing the values in num_ids.txt and checking if each value is greater than the base_num value provided and also if the value is not in “num_ignore” list and then(after first 2 conditions are met) it tries to match numrefs list and prints the matched value in numrefs…

EXPECTEDOUTPUT:-
nums/39/205739/2

import os
import subprocess
def p4 (base_num):
    numrefs = ['nums/89/202089/4', 'nums/39/205739/2', 'nums/94/203455/6']
    num_ignore = [150362, 147117]
    '''
        num_ids.txt
        202089
        205739
        147117
        203455
    '''
    with open('./num_ids.txt', 'rb') as f:
        # Iterate over the file itself
        for line in f:
            num = int(line)
            if num > base_num and num not in num_ignore and line in numrefs:
                print numrefs
def main():
    base_num=203456
    p4(base_num)

    if __name__ == '__main__':
        main()

Answer 1

You can turn the numrefs list into a dict called numrefs_index using a comprehension. That way you can use the in operator and access the references more quickly.

def p4(base_num):
    numrefs = ['nums/89/202089/4', 'nums/39/205739/2', 'nums/94/203455/6']
    num_ignore = [150362, 147117]
    numrefs_index = dict((int(x.split('/')[2]), x) for x in numrefs)
    for line in file("num_ids.txt"):
        num = int(line)
        if num > base_num and num not in num_ignore and num in numrefs_index:
            print numrefs_index[num]

if __name__ == "__main__":
    p4(203456)

# prints:
# nums/39/205739/2

The numrefs_index line builds this dict:

{202089: 'nums/89/202089/4',
 203455: 'nums/94/203455/6',
 205739: 'nums/39/205739/2'}