PS <[EMAIL PROTECTED]> writes:
> Friends,
Please, don't send message bodies to public discussion forums in any
format other than plain text. HTML email in particular has wildly
differing implementations and renderings.
> I am new to python and did search on the web on how to achieve this:
> ( I am trying to append the line numbers to all the lines of a file for now)
> Thanks!!
> =================================================
> import os, sys
> fileName = os.path.join("C:", "temp", "x1.txt")
> fileobject = open(fileName, 'r')
> outputDir = "C://temp//"
> linenumber = 0
> fileName1 = outputDir + " x2.txt"
You've used 'os.path.join' corretly above; you should use that any
time you want to compose a file path.
output_dir = "C://temp//"
out_file_name = os.path.join(output_dir, "x2.txt")
> fileobject1 = open(fileName1, 'w')
> while (1):
> L = fileobject.readline()
> if L=="":
> print "**Done"
> break
A file object is iterable, returning a line of text each time. This
means you don't need to manually loop and extract each line; you can
write this loop as:
out_file = open(out_file_name, 'w')
for in_line in in_file:
# process the line
> linenumber += 1
> fileobject1.write (ln)
The function call syntax doesn't allow a space between the function
name and the opening parenthesis.
You are referencing 'ln' without ever defining it. Presumably you mean
to use 'linenumber'.
linenumber += 1
out_file.write(linenumber)
> fileobject1.write(":: "+ L)
>
> fileobject1.close()
> =============================================================
Wrapping all this advice up::
import os
import sys
in_file_name = os.path.join("C:", "temp", "x1.txt")
in_file = open(in_file_name, 'r')
out_dir = "C://temp//"
out_file_name = os.path.join(out_dir, "x2.txt")
out_file = open(out_file_name, 'w')
linenumber = 0
for in_line in in_file:
linenumber += 1
out_file.write(linenumber)
out_file.write(":: " + in_line)
out_file.close()
in_file.close()
print "**Done"
An improvement would be to use string formatting to construct the
output line:
linenumber = 0
for in_line in in_file:
linenumber += 1
out_line = "%d:: %s" % (linenumber, in_line)
out_file.write(out_line)
This also means you're one easy step away from padding the line number
to a minimum width::
out_line = "%06d:: %s" % (linenumber, in_line)
--
\ "I must say that I find television very educational. The minute |
`\ somebody turns it on, I go to the library and read a book." -- |
_o__) Groucho Marx |
Ben Finney
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