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| author | Senthil Kumaran <orsenthil@gmail.com> | 2010-04-15 17:18:22 (GMT) |
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| committer | Senthil Kumaran <orsenthil@gmail.com> | 2010-04-15 17:18:22 (GMT) |
| commit | b213ee33c03c29c259441e63aba10aa37144a96a (patch) | |
| tree | ce9e66d4e22c61fab69262ac8d426c4c9a41e5dd | |
| parent | 7337a5432bdb804ffe2601bc586d06ac346c3fba (diff) | |
| download | cpython-b213ee33c03c29c259441e63aba10aa37144a96a.zip cpython-b213ee33c03c29c259441e63aba10aa37144a96a.tar.gz cpython-b213ee33c03c29c259441e63aba10aa37144a96a.tar.bz2 | |
Fix Issue5419 - explaining bytes return value of urlopen, use of .decode() to convert to str.
| -rw-r--r-- | Doc/library/urllib.request.rst | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst index f1fe42a..9496083 100644 --- a/Doc/library/urllib.request.rst +++ b/Doc/library/urllib.request.rst @@ -1073,23 +1073,39 @@ Examples -------- This example gets the python.org main page and displays the first 100 bytes of -it:: +it.:: >>> import urllib.request >>> f = urllib.request.urlopen('http://www.python.org/') >>> print(f.read(100)) + b'<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> + <?xml-stylesheet href="./css/ht2html' + +Note that in Python 3, urlopen returns a bytes object by default. In many +circumstances, you might expect the output of urlopen to be a string. This +might be a carried over expectation from Python 2, where urlopen returned +string or it might even the common usecase. In those cases, you should +explicitly decode the bytes to string. + +In the examples below, we have chosen *utf-8* encoding for demonstration, you +might choose the encoding which is suitable for the webpage you are +requesting:: + + >>> import urllib.request + >>> f = urllib.request.urlopen('http://www.python.org/') + >>> print(f.read(100).decode('utf-8') <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <?xml-stylesheet href="./css/ht2html -Here we are sending a data-stream to the stdin of a CGI and reading the data it -returns to us. Note that this example will only work when the Python -installation supports SSL. :: +In the following example, we are sending a data-stream to the stdin of a CGI +and reading the data it returns to us. Note that this example will only work +when the Python installation supports SSL. :: >>> import urllib.request >>> req = urllib.request.Request(url='https://localhost/cgi-bin/test.cgi', ... data='This data is passed to stdin of the CGI') >>> f = urllib.request.urlopen(req) - >>> print(f.read()) + >>> 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:: @@ -1161,7 +1177,7 @@ containing parameters:: >>> 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()) + >>> print(f.read().decode('utf-8')) The following example uses the ``POST`` method instead:: @@ -1169,7 +1185,7 @@ The following example uses the ``POST`` method instead:: >>> 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", params) - >>> print(f.read()) + >>> print(f.read().decode('utf-8')) The following example uses an explicitly specified HTTP proxy, overriding environment settings:: @@ -1178,14 +1194,14 @@ environment settings:: >>> proxies = {'http': 'http://proxy.example.com:8080/'} >>> opener = urllib.request.FancyURLopener(proxies) >>> f = opener.open("http://www.python.org") - >>> f.read() + >>> 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() + >>> f.read().decode('utf-8') :mod:`urllib.request` Restrictions |