ImportError: Missing optional dependency 'jinja2'. DataFrame.style requires jinja2.

[ahbon123]

I've built a exe file using PyInstaller under Windows 10 OS, it successfully generates the exe file, but when I run it, it raise an error:

Exception in Tkinter callback
Traceback (most recent call last):
  File "tkinter\__init__.py", line 1705, in __call__
  File "main_app.py", line 19, in open_directory
  File "data_check.py", line 273, in DataCheck
  File "pandas\core\frame.py", line 836, in style
  File "c:\users\72766\appdata\local\programs\python\python37\lib\site-packages\PyInstaller\loader\pyimod03_importers.py", line 493, in exec_module
    exec(bytecode, module.__dict__)
  File "pandas\io\formats\style.py", line 30, in <module>
  File "pandas\compat\_optional.py", line 92, in import_optional_dependency
ImportError: Missing optional dependency 'jinja2'. DataFrame.style requires jinja2. Use pip or conda to install jinja2.

Please help me to solve this issue. Thanks a lot.

[rokm]

Since jinja2 is optionally imported by pandas, pyinstaller does not collect it. So you either need to add jinja2 to hiddenimports (e.g., pyinstaller --hidden-import jinja2 ...) or explicitly import jinja2 somewhere in your program.

---

But after this, you will hit a new error: NotImplementedError: Can't perform this operation for unregistered loader type. This is due to missing support for pkg_resources provider (#4881), and should be fixed once #5284 is merged.

In the meantime, you can either:

• install pyinstaller branch from hooks: pkg_resources: implement support for package content listing #5284 (i.e., pip install https://github.com/rokm/pyinstaller/archive/pkg-resources.zip
• modify pandas\io\formats\style.py to use jinja2.FileSystemLoader instead of jinja2.PackageLoader` when dealing with a frozen application (see Files not found after packaging #5256 and Error with Folium with unregistered loader type involving list_templates #5262, which had the same issues with retrieving the templates).

---

And after loader issues are solved, you will get jinja2.exceptions.TemplateNotFound: html.tpl, which is due to the html.tpl template data file not being collected.

You can collect it directly using pyinstaller --add-data path-to-site-packages\pandas\io\formats\templates\html.tpl;pandas\io\formats\templates.

Or, you could use PyInstaller.utils.hooks.collect_data_files() in a custom hook or your .spec file to collect data files from pandas.io.formats (or even whole pandas). (There's an existing hook-pandas.py that comes with PyInstaller that you could extend to collect the data as well).

[ahbon123]

Many thanks for your kind help. Sounds complicated, is it caused by the incompatibility of pandas and jinja2 or pyinstaller's bug?

[rokm]

The first part (having to add jinja2 to hiddenimports) is caused by the way pyinstaller works; the other two parts are due to current limitations of pyinstaller and its hooks.

Unfortunately, each python package has its own specifics, so sometimes it takes a bit of an effort to get things packed into an executable...

[ahbon123]

Your answer perfectly solved my issue, thanks a lot.

[lan2720]

@ahbon123
I do as follows

1. pyinstaller --hidden-import jinja2 ...
2. pip install https://github.com/rokm/pyinstaller/archive/pkg-resources.zip
3. modify pandas\io\formats\style.py to use jinja2.FileSystemLoader instead of jinja2.PackageLoader
   But it comes
   
   Could you give some advice?

[bwoodsend]

@lan2720 Thar could be anything. Get rid of the -w option to get a proper stacktrace.

[tsuce]

@lan2720 after step3, run the .py the html.tpl cannot be found. I tried to change code to
loader = jinja2.FileSystemLoader(searchpath="./")
put html.tpl to .py folder or .exe folder, it runs successfully.