title: No module named 'pandas._libs.tslibs.timedeltas' in PyInstaller
body: <p>I am trying to wrap a Python script into an exe using PyInstaller (development version) for windows. </p>
  
  <p>The script uses Pandas and I have been running into an error when running the exe.</p>
  
  <pre><code>Traceback (most recent call last):   File "site-packages\pandas\__init__.py", line 26, in &lt;module&gt;   File "C:\Users\Eddie\Anaconda3\lib\site-packages\PyInstaller\loader\pyimod03_importers.py", line 631, in exec_module
      exec(bytecode, module.__dict__)   File "site-packages\pandas\_libs\__init__.py", line 4, in &lt;module&gt;   File "C:\Users\Eddie\Anaconda3\lib\site-packages\PyInstaller\loader\pyimod03_importers.py", line 714, in load_module
      module = loader.load_module(fullname)   File "pandas/_libs/tslib.pyx", line 1, in init pandas._libs.tslib ModuleNotFoundError: No module named 'pandas._libs.tslibs.timedeltas'
  
  During handling of the above exception, another exception occurred:
  
  Traceback (most recent call last):   File "G5k Version file Extract (with tkinter).py", line 15, in &lt;module&gt;   File "C:\Users\Eddie\Anaconda3\lib\site-packages\PyInstaller\loader\pyimod03_importers.py", line 631, in exec_module
      exec(bytecode, module.__dict__)   File "site-packages\pandas\__init__.py", line 35, in &lt;module&gt; ImportError: C extension: No module named 'pandas._libs.tslibs.timedeltas' not built. If you want to import pandas from the source directory, you may need to run 'python setup.py build_ext --inplace --force' to build the C extensions first.
  </code></pre>
  
  <p>I have tried doing this for programs without pandas and everything was fine.</p>
  
  <p>This is very similar to <a href="https://stackoverflow.com/questions/29109324/pyinstaller-and-pandas/32974358#32974358">another question</a> already solved for Python 2, but I am using Python 3 and that solution does not apply the same way due to the changed .spec file format.</p>
  
  <p>Python 3.6<br>
  PyInstaller - version 3.3<br>
  Pandas - version 0.20.3</p>