#!/bin/env python
# Using generator comprehension on the 'test_regexp.py' regular expression examples

import sys
import fileinput
import re
import string

# print all lines with 'read' event types
file='sample_100k_lines.json'
print ("Reading from ", file)

# -----------------------------------------------------------------------------
# functional version

with open(file,"r") as f:
   xs = (line for line in f
              if  re.search('"event_type":"read"', line))

   # print the results and count matches
   n = 0
   for l in xs:
       n+=1
       # print(l)

   print("Found " + str(n) + " matches")    

# NB: since xs is a generator as well, you can't directly ask for its length
try:
    print("Found " + len(c) + " matches in total")
except:
    print("Error in finding length of a generator comprehension")
    
# NB: this only works, if xs has been expanded before this point
for l in xs:
    print(l)

# -----------------------------------------------------------------------------
# imperative version

def proc_file(file):
   """Find read events in an issuu log file."""
   f = open(file,"r")
   for line in f:
       if re.search('"event_type":"read"', line):
           yield line
   f.close()        
              
def process_file(file):
   """Find read events in an issuu log file."""
   f = open(file,"r")
   line = readline(f)
   while True:
       try:
           if re.search('"event_type":"read"', line):
               yield line
           line = readline(f)
       except StopIteration:
           break
   close(f)        
              
n=0
for l in proc_file(file):
    n += 1
    print(l)

print("IMP: Found " + str(n) + " matches")