Python 2.7 string decode.

Question

In the following Python 2.7 shell, I was expecting "s.decode('cp437')", and print(s) give me the same outputs, but they are not, what's reason here?

>>> import sys
>>> sys.stdout.encoding
'cp437'
>>> sys.stdin.encoding
'cp437'
>>>
>>> s = "Flügel"
>>> s
'Fl\x81gel'
>>> s.decode('cp437')
u'Fl\xfcgel'
>>>
>>> print(s)
Flügel
>>>

• juanpa.arrivillaga: try print(repr(s))
• Pearley: Most likely it's the terminal's encoding that is influencing the encoding here. Try mangling with locales on your system - maybe run LC_ALL=de_DE.cp437 python

Answer 1

This isn't caused by str.decode. When you enter an object in the interactive shell, it prints the representation of that object, not the object itself. For some types, like integers, these display the same thing:

>>> i = 42
>>> i
42
>>> print(repr(i))
42
>>> print(i)
42

For other types, like strings, they display two different things:

>>> s = 'Flügel'
>>> s
'Fl\x81gel'
>>> print(repr(s))
'Fl\x81gel'
>>> print(s)
Flügel

Similarly with a Unicode object:

>>> u = s.decode('cp437')
>>> u
u'Fl\xfcgel'
>>> print(repr(u))
u'Fl\xfcgel'
>>> print(u)
Flügel

It may be helpful (or confusing) to note that in the case of strings and Unicode objects, the object's representation is the Python code to instantiate it. This may be clearer with a demonstration using datetime.datetime, which adopts the same paradigm:

>>> d = datetime.datetime(2012, 12, 20, 23, 59, 59)
>>> d
datetime.datetime(2012, 12, 20, 23, 59, 59)
>>> print(repr(d))
datetime.datetime(2012, 12, 20, 23, 59, 59)
>>> print(d)
2012年12月20日 23:59:59

Answer 2

decode will return the decoded value, not replace s.

If you want to alter your variable,

s = s.decode('cp437')

(Interesting that the documentation simply says it decodes the string, while the encode documentation states it returns an encoded string)

• Pearley: This is irrelevant - at least for the s and s.decode('cp437') commands - their output differ
• Matt S: The question is why print(s) and decode give different results.