python 的requests问题

Question

导入requests,提示报错 ''' UnicodeDecodeError: 'ascii' codec can't decode byte 0xc9 in position 1: ordinal not in range(128)'''
问题查了，一般是字符之间转换的。但是到了库这里，就不懂了什么原因。。。。
小生愚钝，请教各位老师，请指点一二，麻烦了。

导入BeautifulSoup,它是正常的。下面是报错的具体信息。

PS ：不是本专业的，想学习一点计算机方面的。学个爬虫玩玩。英语比较菜。。。

Traceback (most recent call last):
  File "F:/untitled29/lianxi.py", line 5, in <module>
    import requests
  File "F:\Python27\lib\site-packages\requests\__init__.py", line 52, in <module>
    from .packages.urllib3.contrib import pyopenssl
  File "F:\Python27\lib\site-packages\requests\packages\urllib3\contrib\pyopenssl.py", line 47, in <module>
    from cryptography import x509
  File "F:\Python27\lib\site-packages\cryptography\x509\__init__.py", line 7, in <module>
    from cryptography.x509.base import (
  File "F:\Python27\lib\site-packages\cryptography\x509\base.py", line 16, in <module>
    from cryptography.x509.extensions import Extension, ExtensionType
  File "F:\Python27\lib\site-packages\cryptography\x509\extensions.py", line 14, in <module>
    from asn1crypto.keys import PublicKeyInfo
  File "F:\Python27\lib\site-packages\asn1crypto\keys.py", line 22, in <module>
    from ._elliptic_curve import (
  File "F:\Python27\lib\site-packages\asn1crypto\_elliptic_curve.py", line 51, in <module>
    from ._int import inverse_mod
  File "F:\Python27\lib\site-packages\asn1crypto\_int.py", line 56, in <module>
    from ._perf._big_num_ctypes import libcrypto
  File "F:\Python27\lib\site-packages\asn1crypto\_perf\_big_num_ctypes.py", line 31, in <module>
    libcrypto_path = find_library('crypto')
  File "F:\Python27\lib\ctypes\util.py", line 51, in find_library
    fname = os.path.join(directory, name)
  File "F:\Python27\lib\ntpath.py", line 85, in join
    result_path = result_path + p_path
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc9 in position 1: ordinal not in range(128)

Answer 1

如果只是玩一玩的话可以考虑直接使用Python3，比起Python2，Python3的字符编码问题会少很多。

Answer 2

看你的错误提示应该lanxi.py的编码格式有问题，你可以先到cmd控制台运行python再import试一下，应该不是requests有问题

Answer 3

ssl 的加密功能包的文件夹路径有特殊字符

换py3吧， 2总有各种各样的编码问题

Answer 4

result_path = result_path + p_path 

这句代码的变量是不是有中文, 你可以都打印出来看看, 或者将它们都以unicode的形式存

result_path = u'xxx'
p_path = u'xxx'
或者 通过decode函数将变量转成unicode

Answer 5

UnicodeDecodeError是字符解码失败的原因，这不仅是requests的问题，也不仅是python的问题，所有编程语言都有这样的“问题”，也就是必须要了解字符编码。具体的字符编码可以查询资料。下面py2中的字符编码问题。

py2的用引号声明的字串类型都是str，字串前加一个u声明的才是unicode。网络IO，文件读写中传输的字符都是编码成bytes，即str类型。载入到计算机执行计算，一般都要解码成unicode。py2的str方法实际上是''.encode('ascii'), unicode方法是''.decode('ascii')

In [1]: s = u'你好'

In [2]: str(s)
---------------------------------------------------------------------------
UnicodeEncodeError                        Traceback (most recent call last)
<ipython-input-2-d22ffcdd2ee9> in <module>()
----> 1 str(s)

UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-1: ordinal not in range(128)

In [3]: s.decode('ascii')
---------------------------------------------------------------------------
UnicodeEncodeError                        Traceback (most recent call last)
<ipython-input-3-735804de5fd4> in <module>()
----> 1 s.decode('ascii')

UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-1: ordinal not in range(128)

In [4]: ss = '你好'

In [5]: unicode(ss)
---------------------------------------------------------------------------
UnicodeDecodeError                        Traceback (most recent call last)
<ipython-input-5-6325006f91c2> in <module>()
----> 1 unicode(ss)

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe4 in position 0: ordinal not in range(128)

In [6]: ss.decode('ascii')
---------------------------------------------------------------------------
UnicodeDecodeError                        Traceback (most recent call last)
<ipython-input-6-b5dcf2f3b46d> in <module>()
----> 1 ss.decode('ascii')

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe4 in position 0: ordinal not in range(128)

In [7]: ss.decode('utf-8')
Out[7]: u'\u4f60\u597d'

In [8]: ss.decode('gbk')
Out[8]: u'\u6d63\u72b2\u30bd'

因为ss = '你好'是非ascii字符，因此以ascii方式解码失败，当解码成utf-8和gbk就成功了。同理s=u'你好'也不能编码成ascii的方式。

你上面的问题，应该是非ascii字符，decode成ascii字符的时候抛错。result_path + p_path 即这两个变量中，有一个变量是包含非ascii字符的str类型：

In [1]: 'hello' + u'world'
Out[1]: u'helloworld'

In [2]: 'hello' + u'世界'
Out[2]: u'hello\u4e16\u754c'

In [3]: '你好' + u'世界'
---------------------------------------------------------------------------
UnicodeDecodeError                        Traceback (most recent call last)
<ipython-input-3-8c1827afc847> in <module>()
----> 1 '你好' + u'世界'

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe4 in position 0: ordinal not in range(128)

In [4]: '你好' + '世界'
Out[4]: '\xe4\xbd\xa0\xe5\xa5\xbd\xe4\xb8\x96\xe7\x95\x8c'

In [5]: '你好' + '世界 world'
Out[5]: '\xe4\xbd\xa0\xe5\xa5\xbd\xe4\xb8\x96\xe7\x95\x8c world'

In [6]: '你好' + u'世界 world'
---------------------------------------------------------------------------
UnicodeDecodeError                        Traceback (most recent call last)
<ipython-input-6-dcdf837ec675> in <module>()
----> 1 '你好' + u'世界 world'

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe4 in position 0: ordinal not in range(128)

In [9]: '你好' + u'world'
---------------------------------------------------------------------------
UnicodeDecodeError                        Traceback (most recent call last)
<ipython-input-9-1be7bc8e74d5> in <module>()
----> 1 '你好' + u'world'

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe4 in position 0: ordinal not in range(128)

'你好'中的中文不是ascii字符，和unicode字符拼接的时候，会解码成unicode再拼接，对于最后的例子，'你好' + u'world'，其实执行的是 '你好'.decode('ascii') + u'world'，所以就报错。

校正的方式很简单，统一字符编码就好。linux的py默认编码是utf-8，win貌似是gbk。不管怎么样，总之都用utf-8吧。

In [10]: '你好'.decode('utf-8') + u'world'
Out[10]: u'\u4f60\u597dworld'

py3中，所有引号声明的字串都是unicode。也就不存在str和unicode这两种类型。其中str编码成bytes类型，bytes解码成字串类型。两种的相互转换的时候，还是会有 UnicodeDecodeError 问题，不要以为用了py3就能万事大吉，解决的问题关键是知道如何编码解码，就能一劳永逸。

>>> s = '中文'
>>> s.encode('utf-8')
b'\xe4\xb8\xad\xe6\x96\x87'
>>> s.encode('ascii')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-1: ordinal not in range(128)
>>> print(type(s.encode('utf-8')))
<class 'bytes'>
>>> print(type(s))
<class 'str'>