Count line no. using python

Question

Possible Duplicate:
How to get line count cheaply in Python?

In my work i need to open a file and count no. of lines in that, i tried with this

Last_Line = len(open(File_Name).readlines())

It was working fine. Now i have a problem, actual no. of lines in the file is 453, but if i print Last_Line it is showing only 339. If i try

print linecache.getline(File_Name, 350)

it is displaying the contents of line no. 350.

I tried opening the file in all modes. Whether its problem with file or with my logic? Please help.

thank you

What does "all modes" mean? Did you try universal line ending mode? — Ignacio Vazquez-Abrams, Jan 16 '13 at 09:39
Not a duplicate. That one asks "how do I do it?", this one asks "what's wrong with how I'm doing it?". — Ignacio Vazquez-Abrams, Jan 16 '13 at 09:40
@IgnacioVazquez-Abrams I tried with these modes,'r','rb', 'r+' — user19911303, Jan 16 '13 at 09:45
@user1752489 Which IDE? What is the IDE setting for the type of line ending? — Michael J. Barber, Jan 16 '13 at 10:22
@MichaelJ.Barber Using Code blocks on windows. Eol is in standard windows form CRLF — user19911303, Jan 16 '13 at 10:30
@Antony Hatchkins linecache is to read any line in a file http://docs.python.org/2/library/linecache.html — user19911303, Jan 16 '13 at 10:33
**Do not remove the system-generated banner. Doing so may lead to further moderator action. CONSIDER THOSE BANNERS OFF LIMITS WHEN IT COMES TO EDITING.** — casperOne, Feb 08 '13 at 12:56

Michael J. Barber · Accepted Answer · 2013-01-16T10:34:18.807

You have mixed line endings. Your IDE is treating them all as valid, while Python is not. Open the file with the universal newlines flag "U" to have Python take them all as valid line endings.

>>> f = open("file.txt", "w")
>>> f.write("a\rb\nc\r\nd\n\re\n")
>>> f.close()
>>> open("file.txt").readlines()
['a\rb\n', 'c\r\n', 'd\n', '\re\n']
>>> open("file.txt", 'rU').readlines()
['a\n', 'b\n', 'c\n', '\n', 'd\n', '\n', 'e\n']

The documentation for linecache does not appear to specify how it handles line endings. Empirically, it uses universal newlines:

>>> for n in range(1, 8):
...   linecache.getline('file.txt', n)
...
'a\n'
'b\n'
'c\n'
'\n'
'd\n'
'\n'
'e\n'

Count line no. using python

1 Answers1