如何导入已安装的Python模块？

Question

我刚刚使用 pip 安装了一个 Python 包：

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$ sudo pip install py_vollib\nPassword:\nCollecting py_vollib\n  Downloading py_vollib-1.0.1.tar.gz\nCollecting py_lets_be_rational (from py_vollib)\n  Downloading py_lets_be_rational-1.0.1.tar.gz\nRequirement already satisfied: simplejson in /Library/Python/2.7/site-packages (from py_vollib)\nRequirement already satisfied: numpy in /Library/Python/2.7/site-packages (from py_vollib)\nCollecting pandas (from py_vollib)\n  Downloading pandas-0.20.3-cp27-cp27m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl (15.0MB)\n    100% |\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88| 15.1MB 54kB/s\nRequirement already satisfied: scipy in /Library/Python/2.7/site-packages (from py_vollib)\nRequirement already satisfied: pytz>=2011k in /Library/Python/2.7/site-packages (from pandas->py_vollib)\nRequirement already satisfied: python-dateutil in /Library/Python/2.7/site-packages (from pandas->py_vollib)\nRequirement already satisfied: six>=1.5 in /Library/Python/2.7/site-packages (from python-dateutil->pandas->py_vollib)\nInstalling collected packages: py-lets-be-rational, pandas, py-vollib\n  Running setup.py install for py-lets-be-rational ... done\n  Running setup.py install for py-vollib ... done\nSuccessfully installed pandas-0.20.3 py-lets-be-rational-1.0.1 py-vollib-1.0.1\n

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我已经验证它安装正确：

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$ pip freeze | grep vollib\npy-vollib==1.0.1\n

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但我无法在 Python 中导入它：

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$ python\nPython 2.7.13 (default, Jul 20 2017, 18:14:09)\n[GCC 4.2.1 Compatible Apple LLVM 8.1.0 (clang-802.0.42)] on darwin\nType "help", "copyright", "credits" or "license" for more information.\n>>> import py_vollib\nTraceback (most recent call last):\n  File "<stdin>", line 1, in <module>\nImportError: No module named py_vollib\n

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有人知道我在这里做错了什么吗？

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[编辑]

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我已经检查过help(\'modules\')，其中还显示了py_vollib包：

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Answer 1

您正在执行的操作sudo pip install py_vollib是在根环境中安装库。

如果您在 ipython 笔记本或其他东西中执行操作import py_vollib，该模块将不可用。

尝试sudo python然后进行导入

或者

做pip install py_vollib然后python尝试import py_vollib