Python - help（）命令 - 相同的字符串不同的结果

Question

I'm using the python help command with the same string but it's giving different results.

The code:

from BeautifulSoup import BeautifulSoup

link = BeautifulSoup("bilateralFilter")
title = link.getText()

string = "cv2." + title + ""
string2 = "cv2.bilateralFilter"

if string == string2:
    print "----- Output 1 -------------"
    print(type(string))
    help(string)
    print "----- Output 2 -------------"
    print(type(string2))
    help(string2)

Console output:

----- Output 1 -------------
<type 'unicode'>
Help on unicode object:

class unicode(basestring)
 |  unicode(object='') -> unicode object
 |  unicode(string[, encoding[, errors]]) -> unicode object
 ...
----- Output 2 -------------
<type 'str'>
Help on built-in function bilateralFilter in cv2:

cv2.bilateralFilter = bilateralFilter(...)
    bilateralFilter(src, d, sigmaColor, sigmaSpace[, dst[, borderType]]) -> dst

So if it is the same string the help shouldn't be returning the same?

Answer 1

1. title is a unicode object.
2. Therefore "cv2." + title + "" "cv2." + title + "" is also a unicode object.
3. help apparently only accepts non-unicode str s for looking up names, such as string2 .
4. So string and string2 are in fact different types, but str and unicode can still compare equal.
5. You can reproduce the behaviour with title = u'bilateralFilter' or string = u"cv2.bilateralFilter" .