用于已安装包的Python ImportError

Question

Installing表示它已经是最新版本，并且它也显示在pip list返回的列表中，但是导入它会导致导入错误(对于其他已安装的模块，例如for、matplotlib，也存在这个问题)。

系统有什么问题以及如何解决这个问题？

sunny@sunny:~$ pip list
adium-theme-ubuntu (0.3.4)
cycler (0.9.0)
decorator (4.0.6)
matplotlib (1.5.1)
numpy (1.11.0)
Pillow (3.1.2)
pip (8.1.1)
pyeemd (1.3.1)
pyparsing (2.0.3)
python-dateutil (2.4.2)
pytz (2014.10)
scipy (0.17.0)
setuptools (20.7.0)
six (1.10.0)
unity-lens-photos (1.0)
wheel (0.29.0)
sunny@sunny:~$ python
Python 2.7.11 (default, May 28 2016, 17:16:00) 
[GCC 5.3.1 20160413] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named numpy
>>> quit()
sunny@sunny:~$ sudo apt-get install python-numpy
Reading package lists... Done
Building dependency tree       
Reading state information... Done
python-numpy is already the newest version (1:1.11.0-1ubuntu1).
0 upgraded, 0 newly installed, 0 to remove and 5 not upgraded.
sunny@sunny:~$

编辑:我尝试在我的Ubuntu系统上使用pip3 for python3来使导入工作(我以前从未碰过python3 )，并且我再次得到了与上面相同的旧结果

sunny@sunny:~$ pip3 install numpy
Collecting numpy
  Downloading numpy-1.11.1-cp35-cp35m-manylinux1_x86_64.whl (15.6MB)
    100% |████████████████████████████████| 15.6MB 57kB/s 
Installing collected packages: numpy
Successfully installed numpy
You are using pip version 8.1.1, however version 8.1.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
sunny@sunny:~$ python
Python 2.7.11 (default, May 28 2016, 17:16:00) 
[GCC 5.3.1 20160413] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named numpy
>>> quit()
sunny@sunny:~$ pip3 list
apturl (0.5.2)
beautifulsoup4 (4.4.1)
blinker (1.3)
Brlapi (0.6.4)
chardet (2.3.0)
checkbox-support (0.22)
command-not-found (0.3)
cryptography (1.2.3)
defer (1.0.6)
feedparser (5.1.3)
guacamole (0.9.2)
html5lib (0.999)
httplib2 (0.9.1)
idna (2.0)
Jinja2 (2.8)
language-selector (0.1)
louis (2.6.4)
lxml (3.5.0)
Mako (1.0.3)
MarkupSafe (0.23)
numpy (1.11.1)
oauthlib (1.0.3)
onboard (1.2.0)
padme (1.1.1)
pexpect (4.0.1)
Pillow (3.1.2)
pip (8.1.1)
plainbox (0.25)
ptyprocess (0.5)
pyasn1 (0.1.9)
pycups (1.9.73)
pycurl (7.43.0)
pygobject (3.20.0)
PyJWT (1.3.0)
pyparsing (2.0.3)
python-apt (1.1.0b1)
python-debian (0.1.27)
python-systemd (231)
pyxdg (0.25)
reportlab (3.3.0)
requests (2.9.1)
sessioninstaller (0.0.0)
setuptools (20.7.0)
six (1.10.0)
system-service (0.3)
ubuntu-drivers-common (0.0.0)
ufw (0.35)
unattended-upgrades (0.1)
unity-scope-calculator (0.1)
unity-scope-chromiumbookmarks (0.1)
unity-scope-colourlovers (0.1)
unity-scope-devhelp (0.1)
unity-scope-firefoxbookmarks (0.1)
unity-scope-gdrive (0.7)
unity-scope-manpages (0.1)
unity-scope-openclipart (0.1)
unity-scope-texdoc (0.1)
unity-scope-tomboy (0.1)
unity-scope-virtualbox (0.1)
unity-scope-yelp (0.1)
unity-scope-zotero (0.1)
urllib3 (1.13.1)
usb-creator (0.3.0)
wheel (0.29.0)
xdiagnose (3.8.4)
xkit (0.0.0)
XlsxWriter (0.7.3)
You are using pip version 8.1.1, however version 8.1.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
sunny@sunny:~$ 

Answer 1

您为python3.5.*安装了numpy，但是在python2.7.11中导入了它。难到不是么？

sunny@sunny:~$ pip3 install numpy
Collecting numpy
  Downloading numpy-1.11.1-cp35-cp35m-manylinux1_x86_64.whl (15.6MB)
    100% |████████████████████████████████| 15.6MB 57kB/s 
Installing collected packages: numpy
Successfully installed numpy

名字"numpy-1.11.1-cp35-cp35m-manylinux1_x86_64.whl“中的"cp35”指的是python3.5.*。

sunny@sunny:~$ python
Python 2.7.11 (default, May 28 2016, 17:16:00) 
[GCC 5.3.1 20160413] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named numpy

但是在这里，输入"python"，然后打开python2.7.11而不是python3.5。所以，尝试"cd“到python3.5.*的安装目录，然后输入"python3.5.exe”。希望能帮助你。