If statement not working

[oldcity]

Using Linux Mint 18.2 and Python 2.7 with Python 3.5.
Help needed do not understand why the ' if (number == line_num) ' does
not work. The routine continues and gives results for ' expenses-18 '.
How to resolve this?
tia
oldcity

 #!/usr/bin/python3
 #
 ###############################################
 line_num = 1
 with open('Expenses-YY', 'r') as exp_yrs:
     for line in exp_yrs:
         yrs_file = line.strip(",")
         print '(', line_num, ')', yrs_file
         line_num+=1
 #
 #
 number = input(' Enter line #  : ')
 #
 line_num = 0
 with open('Expenses-YY', 'r') as exp_yrs:
     for line in exp_yrs:
         datafile1 = line.strip()
         line_num+=1
         print number, line_num, datafile1
         line_num = int(line_num)
     if (number == line_num):
        datafile = datafile1
 #
 #
 #
 datafile = datafile1.strip()
 #
 print datafile
 with open(datafile, 'r') as exp_data:
     for line in exp_data:
         (pdate,catg,amt,howp) = line.split(',')
         pdate = str(pdate)
         pdate = pdate.strip()
         pdate = str(pdate)
         length = len(pdate)
         howp = howp.strip()
         print pdate, catg, amt, howp

 #   Do stuff here not above line

 print 'job done'
###################################################

 # This is a sample of the resluts.

 ( 1 ) expenses-16

 ( 2 ) expenses-17

 ( 3 ) expenses-18

  Enter line #  : 2
 2 1 expenses-16
 2 2 expenses-17
 2 3 expenses-18

 expenses-18

 010318 2 19.67 2
 010518 5 82.40 2
 010518 6 195.87 2
 050818 2 18.96 2
 051718 3 15.37 2
 052918 1 0.00 2
 job done