[Python-checkins] r59356 - python/trunk/Doc/library/csv.rst python/trunk/Doc/library/pprint.rst python/trunk/Doc/library/traceback.rst
georg.brandl
python-checkins at python.org
Wed Dec 5 18:56:50 CET 2007
Author: georg.brandl
Date: Wed Dec 5 18:56:50 2007
New Revision: 59356
Modified:
python/trunk/Doc/library/csv.rst
python/trunk/Doc/library/pprint.rst
python/trunk/Doc/library/traceback.rst
Log:
Add examples to csv, pprint and traceback docs.
Written by Ross for GHOP.
Modified: python/trunk/Doc/library/csv.rst
==============================================================================
--- python/trunk/Doc/library/csv.rst (original)
+++ python/trunk/Doc/library/csv.rst Wed Dec 5 18:56:50 2007
@@ -45,8 +45,6 @@
.. seealso::
- .. % \seemodule{array}{Arrays of uniformly types numeric values.}
-
:pep:`305` - CSV File API
The Python Enhancement Proposal which proposed this addition to Python.
@@ -77,6 +75,15 @@
All data read are returned as strings. No automatic data type conversion is
performed.
+ A short usage example::
+
+ >>> import csv
+ >>> spamReader = csv.reader(open('eggs.csv'), delimiter=' ', quotechar='|')
+ >>> for row in spamReader:
+ ... print ', '.join(row)
+ Spam, Spam, Spam, Spam, Spam, Baked Beans
+ Spam, Lovely Spam, Wonderful Spam
+
.. versionchanged:: 2.5
The parser is now stricter with respect to multi-line quoted fields. Previously,
if a line ended within a quoted field without a terminating newline character, a
@@ -106,6 +113,14 @@
CSV files without preprocessing the data returned from a ``cursor.fetch*`` call.
All other non-string data are stringified with :func:`str` before being written.
+ A short usage example::
+
+ >>> import csv
+ >>> spamWriter = csv.writer(open('eggs.csv', 'w'), delimiter=' ',
+ ... quotechar='|', quoting=QUOTE_MINIMAL)
+ >>> spamWriter.writerow(['Spam'] * 5 + ['Baked Beans'])
+ >>> spamWriter.writerow(['Spam', 'Lovely Spam', 'Wonderful Spam'])
+
.. function:: register_dialect(name[, dialect][, fmtparam])
Modified: python/trunk/Doc/library/pprint.rst
==============================================================================
--- python/trunk/Doc/library/pprint.rst (original)
+++ python/trunk/Doc/library/pprint.rst Wed Dec 5 18:56:50 2007
@@ -48,30 +48,23 @@
structure cannot be formatted within the constrained width, a best effort will
be made. ::
- >>> import pprint, sys
- >>> stuff = sys.path[:]
+ >>> import pprint
+ >>> stuff = ['spam', 'eggs', 'lumberjack', 'knights', 'ni']
>>> stuff.insert(0, stuff[:])
>>> pp = pprint.PrettyPrinter(indent=4)
>>> pp.pprint(stuff)
- [ [ '',
- '/usr/local/lib/python1.5',
- '/usr/local/lib/python1.5/test',
- '/usr/local/lib/python1.5/sunos5',
- '/usr/local/lib/python1.5/sharedmodules',
- '/usr/local/lib/python1.5/tkinter'],
- '',
- '/usr/local/lib/python1.5',
- '/usr/local/lib/python1.5/test',
- '/usr/local/lib/python1.5/sunos5',
- '/usr/local/lib/python1.5/sharedmodules',
- '/usr/local/lib/python1.5/tkinter']
- >>>
- >>> import parser
- >>> tup = parser.ast2tuple(
- ... parser.suite(open('pprint.py').read()))[1][1][1]
+ [ ['spam', 'eggs', 'lumberjack', 'knights', 'ni'],
+ 'spam',
+ 'eggs',
+ 'lumberjack',
+ 'knights',
+ 'ni']
+ >>> tup = ('spam', ('eggs', ('lumberjack', ('knights', ('ni', ('dead',
+ ... ('parrot', ('fresh fruit',))))))))
>>> pp = pprint.PrettyPrinter(depth=6)
>>> pp.pprint(tup)
- (266, (267, (307, (287, (288, (...))))))
+ ('spam',
+ ('eggs', ('lumberjack', ('knights', ('ni', ('dead', ('parrot', (...,))))))))
The :class:`PrettyPrinter` class supports several derivative functions:
@@ -96,7 +89,8 @@
inspecting values. *indent*, *width* and *depth* will be passed to the
:class:`PrettyPrinter` constructor as formatting parameters. ::
- >>> stuff = sys.path[:]
+ >>> import pprint
+ >>> stuff = ['spam', 'eggs', 'lumberjack', 'knights', 'ni']
>>> stuff.insert(0, stuff)
>>> pprint.pprint(stuff)
[<Recursion on list with id=869440>,
@@ -211,3 +205,38 @@
.. versionadded:: 2.3
+.. _pprint-example:
+
+pprint Example
+--------------
+
+This example demonstrates several uses of the :func:`pprint` function and its parameters.
+
+ >>> import pprint
+ >>> tup = ('spam', ('eggs', ('lumberjack', ('knights', ('ni', ('dead',
+ ... ('parrot', ('fresh fruit',))))))))
+ >>> stuff = ['a' * 10, tup, ['a' * 30, 'b' * 30], ['c' * 20, 'd' * 20]]
+ >>> pprint.pprint(stuff)
+ ['aaaaaaaaaa',
+ ('spam',
+ ('eggs',
+ ('lumberjack',
+ ('knights', ('ni', ('dead', ('parrot', ('fresh fruit',)))))))),
+ ['aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa', 'bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'],
+ ['cccccccccccccccccccc', 'dddddddddddddddddddd']]
+ >>> pprint.pprint(stuff, depth=3)
+ ['aaaaaaaaaa',
+ ('spam', ('eggs', ('lumberjack', (...)))),
+ ['aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa', 'bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'],
+ ['cccccccccccccccccccc', 'dddddddddddddddddddd']]
+ >>> pprint.pprint(stuff, width=60)
+ ['aaaaaaaaaa',
+ ('spam',
+ ('eggs',
+ ('lumberjack',
+ ('knights',
+ ('ni', ('dead', ('parrot', ('fresh fruit',)))))))),
+ ['aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa',
+ 'bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'],
+ ['cccccccccccccccccccc', 'dddddddddddddddddddd']]
+
Modified: python/trunk/Doc/library/traceback.rst
==============================================================================
--- python/trunk/Doc/library/traceback.rst (original)
+++ python/trunk/Doc/library/traceback.rst Wed Dec 5 18:56:50 2007
@@ -137,8 +137,8 @@
.. _traceback-example:
-Traceback Example
------------------
+Traceback Examples
+------------------
This simple example implements a basic read-eval-print loop, similar to (but
less useful than) the standard Python interactive interpreter loop. For a more
@@ -161,3 +161,124 @@
while 1:
run_user_code(envdir)
+
+The following example demonstrates the different ways to print and format the
+exception and traceback::
+
+ import sys, traceback
+
+ def lumberjack():
+ bright_side_of_death()
+
+ def bright_side_of_death():
+ return tuple()[0]
+
+ try:
+ lumberjack()
+ except:
+ exceptionType, exceptionValue, exceptionTraceback = sys.exc_info()
+ print "*** print_tb:"
+ traceback.print_tb(exceptionTraceback, limit=1, file=sys.stdout)
+ print "*** print_exception:"
+ traceback.print_exception(exceptionType, exceptionValue, exceptionTraceback,
+ limit=2, file=sys.stdout)
+ print "*** print_exc:"
+ traceback.print_exc()
+ print "*** format_exc, first and last line:"
+ formatted_lines = traceback.format_exc().splitlines()
+ print formatted_lines[0]
+ print formatted_lines[-1]
+ print "*** format_exception:"
+ print repr(traceback.format_exception(exceptionType, exceptionValue,
+ exceptionTraceback))
+ print "*** extract_tb:"
+ print repr(traceback.extract_tb(exceptionTraceback))
+ print "*** format_tb:"
+ print repr(traceback.format_tb(exceptionTraceback))
+ print "*** tb_lineno:", traceback.tb_lineno(exceptionTraceback)
+ print "*** print_last:"
+ traceback.print_last()
+
+
+The output for the example would look similar to this::
+
+ *** print_tb:
+ File "<doctest>", line 9, in <module>
+ lumberjack()
+ *** print_exception:
+ Traceback (most recent call last):
+ File "<doctest>", line 9, in <module>
+ lumberjack()
+ File "<doctest>", line 3, in lumberjack
+ bright_side_of_death()
+ IndexError: tuple index out of range
+ *** print_exc:
+ Traceback (most recent call last):
+ File "<doctest>", line 9, in <module>
+ lumberjack()
+ File "<doctest>", line 3, in lumberjack
+ bright_side_of_death()
+ IndexError: tuple index out of range
+ *** format_exc, first and last line:
+ Traceback (most recent call last):
+ IndexError: tuple index out of range
+ *** format_exception:
+ ['Traceback (most recent call last):\n',
+ ' File "<doctest>", line 9, in <module>\n lumberjack()\n',
+ ' File "<doctest>", line 3, in lumberjack\n bright_side_of_death()\n',
+ ' File "<doctest>", line 6, in bright_side_of_death\n return tuple()[0]\n',
+ 'IndexError: tuple index out of range\n']
+ *** extract_tb:
+ [('<doctest>', 9, '<module>', 'lumberjack()'),
+ ('<doctest>', 3, 'lumberjack', 'bright_side_of_death()'),
+ ('<doctest>', 6, 'bright_side_of_death', 'return tuple()[0]')]
+ *** format_tb:
+ [' File "<doctest>", line 9, in <module>\n lumberjack()\n',
+ ' File "<doctest>", line 3, in lumberjack\n bright_side_of_death()\n',
+ ' File "<doctest>", line 6, in bright_side_of_death\n return tuple()[0]\n']
+ *** tb_lineno: 2
+ *** print_last:
+ Traceback (most recent call last):
+ File "<doctest>", line 9, in <module>
+ lumberjack()
+ File "<doctest>", line 3, in lumberjack
+ bright_side_of_death()
+ IndexError: tuple index out of range
+
+
+The following example shows the different ways to print and format the stack::
+
+ >>> import traceback
+ >>> def another_function():
+ ... lumberstack()
+ ...
+ >>> def lumberstack():
+ ... traceback.print_stack()
+ ... print repr(traceback.extract_stack())
+ ... print repr(traceback.format_stack())
+ ...
+ >>> another_function()
+ File "<doctest>", line 10, in <module>
+ another_function()
+ File "<doctest>", line 3, in another_function
+ lumberstack()
+ File "<doctest>", line 6, in lumberstack
+ traceback.print_stack()
+ [('<doctest>', 10, '<module>', 'another_function()'),
+ ('<doctest>', 3, 'another_function', 'lumberstack()'),
+ ('<doctest>', 7, 'lumberstack', 'print repr(traceback.extract_stack())')]
+ [' File "<doctest>", line 10, in <module>\n another_function()\n',
+ ' File "<doctest>", line 3, in another_function\n lumberstack()\n',
+ ' File "<doctest>", line 8, in lumberstack\n print repr(traceback.format_stack())\n']
+
+
+This last example demonstrates the final few formatting functions::
+
+ >>> import traceback
+ >>> format_list([('spam.py', 3, '<module>', 'spam.eggs()'),
+ ... ('eggs.py', 42, 'eggs', 'return "bacon"')])
+ [' File "spam.py", line 3, in <module>\n spam.eggs()\n',
+ ' File "eggs.py", line 42, in eggs\n return "bacon"\n']
+ >>> theError = IndexError('tuple indx out of range')
+ >>> traceback.format_exception_only(type(theError), theError)
+ ['IndexError: tuple index out of range\n']
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