From f453debb45e81fb81bf18a0089868212ac29c19d Mon Sep 17 00:00:00 2001 From: R David Murray Date: Sun, 20 Mar 2011 10:23:22 -0400 Subject: [PATCH] #7198: really add newline='' to csv.writer docs. Changeset ab27f16f707a was messed up by a rebase (as were 959f666470cc and 9d1b1a95bc8f) and the patch only got applied to default. --- Doc/library/csv.rst | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/Doc/library/csv.rst b/Doc/library/csv.rst index a2dfd17a47a..1dd8aa831ba 100644 --- a/Doc/library/csv.rst +++ b/Doc/library/csv.rst @@ -52,7 +52,7 @@ The :mod:`csv` module defines the following functions: *csvfile* can be any object which supports the :term:`iterator` protocol and returns a string each time its :meth:`!__next__` method is called --- :term:`file objects ` and list objects are both suitable. If *csvfile* is a file object, - it should be opened with ``newline=''``. [#]_ An optional + it should be opened with ``newline=''``. [1]_ An optional *dialect* parameter can be given which is used to define a set of parameters specific to a particular CSV dialect. It may be an instance of a subclass of the :class:`Dialect` class or one of the strings returned by the @@ -79,7 +79,8 @@ The :mod:`csv` module defines the following functions: Return a writer object responsible for converting the user's data into delimited strings on the given file-like object. *csvfile* can be any object with a - :func:`write` method. An optional *dialect* + :func:`write` method. If csvfile is a file object, it should be opened with + newline='' [1]_. An optional *dialect* parameter can be given which is used to define a set of parameters specific to a particular CSV dialect. It may be an instance of a subclass of the :class:`Dialect` class or one of the strings returned by the @@ -96,7 +97,7 @@ The :mod:`csv` module defines the following functions: A short usage example:: >>> import csv - >>> spamWriter = csv.writer(open('eggs.csv', 'w'), delimiter=' ', + >>> spamWriter = csv.writer(open('eggs.csv', 'w', newline=''), delimiter=' ', ... quotechar='|', quoting=csv.QUOTE_MINIMAL) >>> spamWriter.writerow(['Spam'] * 5 + ['Baked Beans']) >>> spamWriter.writerow(['Spam', 'Lovely Spam', 'Wonderful Spam']) @@ -408,7 +409,7 @@ The simplest example of reading a CSV file:: Reading a file with an alternate format:: import csv - with open('passwd') as f: + with open('passwd', newline='') as f: reader = csv.reader(f, delimiter=':', quoting=csv.QUOTE_NONE) for row in reader: print(row) @@ -416,7 +417,7 @@ Reading a file with an alternate format:: The corresponding simplest possible writing example is:: import csv - with open('some.csv', 'w') as f: + with open('some.csv', 'w', newline='') as f: writer = csv.writer(f) writer.writerows(someiterable) @@ -438,7 +439,7 @@ Registering a new dialect:: import csv csv.register_dialect('unixpwd', delimiter=':', quoting=csv.QUOTE_NONE) - with open('passwd') as f: + with open('passwd', newline='') as f: reader = csv.reader(f, 'unixpwd') A slightly more advanced use of the reader --- catching and reporting errors:: @@ -463,7 +464,7 @@ done:: .. rubric:: Footnotes -.. [#] If ``newline=''`` is not specified, newlines embedded inside quoted fields - will not be interpreted correctly. It should always be safe to specify - ``newline=''``, since the csv module does its own universal newline handling - on input. +.. [1] If ``newline=''`` is not specified, newlines embedded inside quoted fields + will not be interpreted correctly, and on platforms that use ``\r\n`` linendings + on write an extra `\\r` will be added. It should always be safe to specify + ``newline=''``, since the csv module does its own (universal) newline handling.