I am trying to wrap a Python script into an exe using PyInstaller (development version) for windows. 

The script uses Pandas and I have been running into an error when running the exe.

```
Traceback (most recent call last):   File "site-packages\pandas\__init__.py", line 26, in <module>   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 <module>   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 <module>   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 <module> 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.

```

I have tried doing this for programs without pandas and everything was fine.

This is very similar to [another question](https://stackoverflow.com/questions/29109324/pyinstaller-and-pandas/32974358#32974358) 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.

Python 3.6  

PyInstaller - version 3.3  

Pandas - version 0.20.3
['https://Stackoverflow.com/questions/47318119', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/8436718/']
PyInstaller 3.3, Pandas 0.21.0, Python 3.6.1.

I was able to solve this thanks to not-yet published/committed fix to PyInstaller, see [this](https://github.com/pyinstaller/pyinstaller/issues/2978) and [this](https://github.com/lneuhaus/pyinstaller/blob/017b247064f9bd51a620cfb2172c05d63fc75133/PyInstaller/hooks/hook-pandas.py). AND keeping the ability to pack it into one executable file.

Basically:

1. Locate PyInstaller folder..\hooks, e.g. `C:\Program Files\Python\Lib\site-packages\PyInstaller\hooks`.
2. Create file hook-pandas.py with contents (or anything similar based on your error):

```
hiddenimports = ['pandas._libs.tslibs.timedeltas']

```
3. Save it + I deleted .spec file, build and dist folders just to be sure.
4. Run `pyinstaller -F my_app.py`.

This fix should work as long as you don't upgrade or reinstall PyInstaller. So you don't need to edit .spec file.

Maybe they will include the fix sooner for us! :)
I managed to solve this problem by using the "--hidden-import" flag. Hopefully this can be helpful to someone else that comes across this thread.

```
pyinstaller --onefile --hidden-import pandas._libs.tslibs.timedeltas myScript.py

```