AttributeError: 'NoneType' object has no attribute 'loader'

I have downloaded manimlib, (with pip3) as well as cairo, ffmpeg, and sox. (with brew)

I tried to run this program, enteringmanim Manim Demo.py Shapes -pl into my command line, which worked here for someone with a seemingly the same problem:

from manimlib.imports import *

class Shapes(Scene):
    def construct(self):
        circle = Circle()
        square = Square()
        line=Line(np.array([3,0,0]),np.array([5,0,0]))
        triangle=Polygon(np.array([0,0,0]),np.array([1,1,0]),np.array([1,-1,0]))

        self.add(line)
        self.play(ShowCreation(circle))
        self.play(FadeOut(circle))
        self.play(GrowFromCenter(square))
        self.play(Transform(square,triangle))

This gave the following error:

Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.7/bin/manim", line 10, in <module>
    sys.exit(main())
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/manimlib/__init__.py", line 11, in main
    config = manimlib.config.get_configuration(args)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/manimlib/config.py", line 185, in get_configuration
    module = get_module(args.file)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/manimlib/config.py", line 179, in get_module
    module = importlib.util.module_from_spec(spec)
  File "<frozen importlib._bootstrap>", line 580, in module_from_spec
AttributeError: 'NoneType' object has no attribute 'loader'

I just recently downloaded macOS Catalina, (10.15.4), and am using Python 3.7.

[zoladon]

Nevermind I fixed it!

[tinfungster]

Check whether your file name is right in the terminal.