this is one of my exercises in Python ebook. I just wonder if it is possible to use WHILE instead of FOR. Thanks for your help
#Ask the user to enter a regular expression #count the number of lines that matched the regular expression.
My code
x= input('Enter a regular expression.')
file = open('mbox-short.txt')
count = 0
for line in file: line=line.rstrip()
if re.search('\\b' + x + '\\b', line):
count=count+1
print (count)
If you really want to step it up a notch, leverage that fact that True and False sum as 1 and 0. This gets rid of explicit for and while completely.
import re
x = input('Enter a regular expression.')
my_regex = '\\b' + x + '\\b'
with open('mbox-short.txt') as f:
count = sum(bool(re.search(my_regex, line)) for line in f)
You can use the while loop as below to perform the same task as below,
import re
x = input('Enter a regular expression.')
fileHandler = open('tmp.txt')
count = 0
while True:
line = fileHandler.readline()
if not line:
break
if re.search('\\b' + x + '\\b', line):
count += 1
print (count)
for or while
x= input('Enter a regular expression.')
file = open('mbox-short.txt')
count = 0
while(re.search('\\b' + x + '\\b', line)):
count = count+1
print(count)
This will work I think so.
try
x= input('Enter a regular expression.')
file = open('mbox-short.txt')
count = 0
temp=0
lines=file.readlines()
while True:
if re.search('\\b' + x + '\\b', lines[temp]):
count=count+1
if temp==len(lines)-1:
break
temp=temp+1
print(count)
