[Python-checkins] cpython (merge 3.4 -> default): Issue #12955: Change the urlopen() examples to use context managers where

Sun Apr 12 12:52:58 CEST 2015

https://hg.python.org/cpython/rev/08adaaf08697
changeset: 95556:08adaaf08697
parent: 95554:684aadcabcc7
parent: 95555:6d5336a193cc
user: Berker Peksag <berker.peksag at gmail.com>
date: Sun Apr 12 13:53:33 2015 +0300
summary:
 Issue #12955: Change the urlopen() examples to use context managers where appropriate.
Patch by Martin Panter.
files:
 Doc/faq/library.rst | 3 +-
 Doc/howto/urllib2.rst | 16 ++++----
 Doc/library/concurrent.futures.rst | 4 +-
 Doc/library/urllib.request.rst | 34 +++++++++++------
 Doc/tutorial/stdlib.rst | 9 ++--
 5 files changed, 38 insertions(+), 28 deletions(-)

diff --git a/Doc/faq/library.rst b/Doc/faq/library.rst
--- a/Doc/faq/library.rst
+++ b/Doc/faq/library.rst
@@ -687,7 +687,8 @@
 ### connect and send the server a path
 req = urllib.request.urlopen('http://www.some-server.out-there'
 '/cgi-bin/some-cgi-script', data=qs)
- msg, hdrs = req.read(), req.info()
+ with req:
+ msg, hdrs = req.read(), req.info()
 
 Note that in general for percent-encoded POST operations, query strings must be
 quoted using :func:`urllib.parse.urlencode`. For example, to send
diff --git a/Doc/howto/urllib2.rst b/Doc/howto/urllib2.rst
--- a/Doc/howto/urllib2.rst
+++ b/Doc/howto/urllib2.rst
@@ -53,8 +53,8 @@
 The simplest way to use urllib.request is as follows::
 
 import urllib.request
- response = urllib.request.urlopen('http://python.org/')
- html = response.read()
+ with urllib.request.urlopen('http://python.org/') as response:
+ html = response.read()
 
 If you wish to retrieve a resource via URL and store it in a temporary location,
 you can do so via the :func:`~urllib.request.urlretrieve` function::
@@ -79,8 +79,8 @@
 import urllib.request
 
 req = urllib.request.Request('http://www.voidspace.org.uk')
- response = urllib.request.urlopen(req)
- the_page = response.read()
+ with urllib.request.urlopen(req) as response:
+ the_page = response.read()
 
 Note that urllib.request makes use of the same Request interface to handle all URL
 schemes. For example, you can make an FTP request like so::
@@ -117,8 +117,8 @@
 data = urllib.parse.urlencode(values)
 data = data.encode('utf-8') # data should be bytes
 req = urllib.request.Request(url, data)
- response = urllib.request.urlopen(req)
- the_page = response.read()
+ with urllib.request.urlopen(req) as response:
+ the_page = response.read()
 
 Note that other encodings are sometimes required (e.g. for file upload from HTML
 forms - see `HTML Specification, Form Submission
@@ -183,8 +183,8 @@
 data = urllib.parse.urlencode(values)
 data = data.encode('utf-8')
 req = urllib.request.Request(url, data, headers)
- response = urllib.request.urlopen(req)
- the_page = response.read()
+ with urllib.request.urlopen(req) as response:
+ the_page = response.read()
 
 The response also has two useful methods. See the section on `info and geturl`_
 which comes after we have a look at what happens when things go wrong.
diff --git a/Doc/library/concurrent.futures.rst b/Doc/library/concurrent.futures.rst
--- a/Doc/library/concurrent.futures.rst
+++ b/Doc/library/concurrent.futures.rst
@@ -155,8 +155,8 @@
 
 # Retrieve a single page and report the url and contents
 def load_url(url, timeout):
- conn = urllib.request.urlopen(url, timeout=timeout)
- return conn.readall()
+ with urllib.request.urlopen(url, timeout=timeout) as conn:
+ return conn.read()
 
 # We can use a with statement to ensure threads are cleaned up promptly
 with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -1060,8 +1060,9 @@
 it. ::
 
 >>> import urllib.request
- >>> f = urllib.request.urlopen('http://www.python.org/')
- >>> print(f.read(300))
+ >>> with urllib.request.urlopen('http://www.python.org/') as f:
+ ... print(f.read(300))
+ ...
 b'<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">\n\n\n<html
 xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">\n\n<head>\n
@@ -1103,8 +1104,9 @@
 >>> import urllib.request
 >>> req = urllib.request.Request(url='https://localhost/cgi-bin/test.cgi',
 ... data=b'This data is passed to stdin of the CGI')
- >>> f = urllib.request.urlopen(req)
- >>> print(f.read().decode('utf-8'))
+ >>> with urllib.request.urlopen(req) as f:
+ ... print(f.read().decode('utf-8'))
+ ...
 Got Data: "This data is passed to stdin of the CGI"
 
 The code for the sample CGI used in the above example is::
@@ -1119,7 +1121,8 @@
 import urllib.request
 DATA=b'some data'
 req = urllib.request.Request(url='http://localhost:8080', data=DATA,method='PUT')
- f = urllib.request.urlopen(req)
+ with urllib.request.urlopen(req) as f:
+ pass
 print(f.status)
 print(f.reason)
 
@@ -1185,8 +1188,10 @@
 >>> import urllib.request
 >>> import urllib.parse
 >>> params = urllib.parse.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
- >>> f = urllib.request.urlopen("http://www.musi-cal.com/cgi-bin/query?%s" % params)
- >>> print(f.read().decode('utf-8'))
+ >>> url = "http://www.musi-cal.com/cgi-bin/query?%s" % params
+ >>> with urllib.request.urlopen(url) as f:
+ ... print(f.read().decode('utf-8'))
+ ...
 
 The following example uses the ``POST`` method instead. Note that params output
 from urlencode is encoded to bytes before it is sent to urlopen as data::
@@ -1198,8 +1203,9 @@
 >>> request = urllib.request.Request("http://requestb.in/xrbl82xr")
 >>> # adding charset parameter to the Content-Type header.
 >>> request.add_header("Content-Type","application/x-www-form-urlencoded;charset=utf-8")
- >>> f = urllib.request.urlopen(request, data)
- >>> print(f.read().decode('utf-8'))
+ >>> with urllib.request.urlopen(request, data) as f:
+ ... print(f.read().decode('utf-8'))
+ ...
 
 The following example uses an explicitly specified HTTP proxy, overriding
 environment settings::
@@ -1207,15 +1213,17 @@
 >>> import urllib.request
 >>> proxies = {'http': 'http://proxy.example.com:8080/'}
 >>> opener = urllib.request.FancyURLopener(proxies)
- >>> f = opener.open("http://www.python.org")
- >>> f.read().decode('utf-8')
+ >>> with opener.open("http://www.python.org") as f:
+ ... f.read().decode('utf-8')
+ ...
 
 The following example uses no proxies at all, overriding environment settings::
 
 >>> import urllib.request
 >>> opener = urllib.request.FancyURLopener({})
- >>> f = opener.open("http://www.python.org/")
- >>> f.read().decode('utf-8')
+ >>> with opener.open("http://www.python.org/") as f:
+ ... f.read().decode('utf-8')
+ ...
 
 
 Legacy interface
diff --git a/Doc/tutorial/stdlib.rst b/Doc/tutorial/stdlib.rst
--- a/Doc/tutorial/stdlib.rst
+++ b/Doc/tutorial/stdlib.rst
@@ -153,10 +153,11 @@
 from URLs and :mod:`smtplib` for sending mail::
 
 >>> from urllib.request import urlopen
- >>> for line in urlopen('http://tycho.usno.navy.mil/cgi-bin/timer.pl'):
- ... line = line.decode('utf-8') # Decoding the binary data to text.
- ... if 'EST' in line or 'EDT' in line: # look for Eastern Time
- ... print(line)
+ >>> with urlopen('http://tycho.usno.navy.mil/cgi-bin/timer.pl') as response:
+ ... for line in response:
+ ... line = line.decode('utf-8') # Decoding the binary data to text.
+ ... if 'EST' in line or 'EDT' in line: # look for Eastern Time
+ ... print(line)
 
 <BR>Nov. 25, 09:43:32 PM EST
 
-- 
Repository URL: https://hg.python.org/cpython
