Debugging ImportError: No module named arcpy

This error is discussed near the bottom of the Importing ArcPy documentation page where there are some additional notes about ArcGIS 10.2.x (if that is the version that you are using):

Tip: If importing ArcPy produces either of the following errors, the required modules could not be found:

• ImportError: No module named arcpy
• ImportError: No module named arcgisscripting

To address this, browse using Windows Explorer to the python27\Lib\site-packages folder and add or edit the Desktop10.2.2.pth file. The file should contain the three lines shown below (corrected to your system's path if they do not match):

---

c:\Program Files\ArcGIS\Desktop10.2.2\arcpy
c:\Program Files\ArcGIS\Desktop10.2.2\bin
c:\Program Files\ArcGIS\Desktop10.2.2\ArcToolbox\Scripts

@PolyGeo's solution is top-notch, but not perfect for every use case.

For example, in my use case, I had a Python 2.7.11 install on my machine and then I installed ArcGIS which came with Python 2.7.8. When I followed the instructions at Importing ArcPy, I found that the path C:\Python27\ArcGIS10.3\Lib\site-packages had a file called Desktop10.3.pth in it with the following lines:

C:\Program Files (x86)\ArcGIS\Desktop10.3\bin
C:\Program Files (x86)\ArcGIS\Desktop10.3\ArcPy
C:\Program Files (x86)\ArcGIS\Desktop10.3\ArcToolBox\Scripts

Yet, I still could not get ArcPy to import w/o error. I found that this is because the Python path being used by my machine is the 2.7.11 path, rather than the 2.7.8 path (the ArcGIS-specific Python install). Even if you include the correct path inside your Windows Environment Variables, it will not work because when you type python into the Command Line Interface, Windows does not know which Python install to use.

This is my work-around:

1. Navigate to C:\Python27. You should see a folder called ArcGIS10.3 or whichever version you have installed.

2. Click into ArcGIS10.3 and locate the Python.exe executable. Copy/paste this exe and rename it arcpy or something else that you can remember.

3. Make sure you have added the C:\Python27\ArcGIS10.3 directory into your path in your Windows Environment Variables.

4. Open a new cmd and type the name you used (i.e. arcpy). You should see a Python interpreter open up and you should see the correct version 2.7.8. If this is all correct, try typing import arcpy into the interpreter. If it works, you have been successful!

This problem happens for me because the path of ArcGIS was in Program File(x86) instead of normal place(program file). there are two methods to fix the problem:

1. you can change the path of python for example by PyScripter (it has a function to change the path) or

2. the easiest way is: change the name of python27's folder to python27_old. in control panel click on program and feature, choose uninstall/change and repair ArcGIS. it will install python again with correct path. It worked for me.