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Kaydet (Commit) 722e1011 authored tarafından Georg Brandl's avatar Georg Brandl
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Add examples to csv, pprint and traceback docs. 

Written by Ross for GHOP.
üst 395fe442
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Doc/library/csv.rst
Dosyayı görüntüle @ 722e1011
......@@ -45,8 +45,6 @@ using the :class:`DictReader` and :class:`DictWriter` classes.
.. 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 @@ The :mod:`csv` module defines the following functions:
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 @@ The :mod:`csv` module defines the following functions:
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])
......
Doc/library/pprint.rst
Dosyayı görüntüle @ 722e1011
......@@ -48,30 +48,23 @@ The :mod:`pprint` module defines one class:
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 @@ The :class:`PrettyPrinter` class supports several derivative functions:
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 @@ are converted to strings. The default implementation uses the internals of the
.. 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']]
Doc/library/traceback.rst
Dosyayı görüntüle @ 722e1011
......@@ -137,8 +137,8 @@ The module defines the following functions:
.. _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 @@ module. ::
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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