When importing a module without null bytes I get ValueError: source code string cannot contain null bytes

Question

Python isn't importing modules!

marketing
    ├───__init__.py
    ├───analyzation\
    │   ├───__init__.py
    │   ├───analyzer.py
    ├───api\
    ├───test\
    │   ├───test_res\ (not important)
    │   ├───__init__.py
    │   ├───test_analyzer.py

Above is my folder structure. So, in analyzer.py I have a class DataSet and nothing else other than some imports from pandas and an import in a method import random.

In test_analyzer.py I have a class that subclasses unittest.TestCase. This script tries to test the following class being imported: import marketing.analyzation.analyzer (which doesn't work). The error message is the following:

Traceback (most recent call last):
  File ".\test_analyzer.py", line 1, in <module>
    import marketing.analyzation.analyzer
ValueError: source code string cannot contain null bytes

Just to make sure it wasn't some dumb vim error, I retyped analyzer.py. Spent at least 2 hours trying to fix this, and another hour surfing stackoverflow and googling, but so far I've come up with nothing. Is it because test_analyzer.py is in its own submodule?

Thanks~~~

Probably dupe of https://stackoverflow.com/questions/31233777/python-source-code-string-cannot-contain-null-bytes but I can't verify now. — Dimitris Fasarakis Hilliard, Jul 31 '17 at 23:52
@matt961: If you rename `analyzer.py` to `analyzer2.py` (without changing the import), does the error change? — Ry-, Jul 31 '17 at 23:55
Are you doing this under Windows? Did you use Notepad? It smells like the file was saved as Unicode rather than plain ole ASCII. — John Szakmeister, Aug 01 '17 at 00:19
@MichaelO. Oh my god. I was creating `__init__.py` by powershell CLI using `'' > __init__.py`. Damn you windows. — matt961, Aug 01 '17 at 00:23
https://stackoverflow.com/questions/5596982/using-powershell-to-write-a-file-in-utf-8-without-the-bom — bruno desthuilliers, Jul 08 '19 at 11:08

score 0 · Answer 1 · answered Aug 01 '17 at 00:25

0

Don't use powershell to create files being read by python. Used Vim to create __init__.py files instead. Thanks commenters.

answered Aug 01 '17 at 00:25

matt961

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score 0 · Answer 2 · answered May 28 '20 at 07:18

0

I had similar problem with pytest.

In my case the problem was in __init__.py: the file was created in UTF-16 encoding. I changed encoding to UTF-8 and the problem disappeared.

answered May 28 '20 at 07:18

feeeper

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When importing a module without null bytes I get ValueError: source code string cannot contain null bytes

2 Answers2