没有名为psycopg2的模块和请求

Question

我正在Mac（Sierra）中运行QGIS，但由于此错误而无法加载处理插件：

>>> Couldn't load plugin 'processing' 
ImportError: No module named psycopg2 
Traceback (most recent call last):
  File .     "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 308, in loadPlugin
__import__(packageName)
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 607, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/__init__.py", line 29, in 
from processing.tools.general import *              # NOQA
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 607, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/tools/general.py", line 31, in 
from processing.core.Processing import Processing
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 607, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/core/Processing.py", line 42, in 
from processing.script.ScriptUtils import ScriptUtils
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 607, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/script/ScriptUtils.py", line 30, in 
from processing.script.ScriptAlgorithm import ScriptAlgorithm
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 607, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/script/ScriptAlgorithm.py", line 33, in 
from processing.core.GeoAlgorithm import GeoAlgorithm
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 607, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/core/GeoAlgorithm.py", line 41, in 
from processing.core.parameters import ParameterRaster, ParameterVector, ParameterMultipleInput, ParameterTable, Parameter
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 607, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/core/parameters.py", line 32, in 
from processing.tools.vector import resolveFieldIndex
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 607, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/plugins/processing/tools/vector.py", line 35, in 
import psycopg2
  File "/usr/local/Cellar/qgis2/2.18.21/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 607, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
ImportError: No module named psycopg2
Python version: 2.7.15 (default, Jul  2 2018, 01:42:08) [GCC 4.2.1 
Compatible Apple LLVM 9.1.0 (clang-902.0.39.2)] 
QGIS version: 2.18.21 Las Palmas, exported 

A从此链接中找到了类似的帖子：

[链接到上一篇文章]（ImportError: No module named requests）

当我在python窗口中键入import requests和import psycopg2时，我没有收到任何错误：

任何想法为什么会这样？ 我将不胜感激。

Answer 1

尝试安装这些软件包

pip install psycopg2-binary requests

Answer 2

由于您可以在计算机上安装各种版本的Python，因此要确保pip install psycopg2-binary requests确实适用于您的QGIS Python环境并不总是那么简单。

您可能希望通过以下操作从QGIS Python console安装软件包：

from pip._internal import main as pipmain

pipmain(['install', 'psycopg2-binary', 'requests'])