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authorR David Murray <rdmurray@bitdance.com>2011-03-20 14:23:22 (GMT)
committerR David Murray <rdmurray@bitdance.com>2011-03-20 14:23:22 (GMT)
commitf453debb45e81fb81bf18a0089868212ac29c19d (patch)
treeaa6c669ad471974be8eb21bbcf72c71e8475d912
parent1b407fe658fb298986d1ed3f8a71937ac1b3460c (diff)
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#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.
-rw-r--r--Doc/library/csv.rst21
1 files changed, 11 insertions, 10 deletions
diff --git a/Doc/library/csv.rst b/Doc/library/csv.rst
index a2dfd17..1dd8aa8 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
<file object>` 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.