SyntaxError: invalid syntax - %pylab

Question

Unfortunately I am not a programmer and I am encountering the error:

$ python3 code.py
   File "code.py", line 7
     % pylab inline
     ^
SyntaxError: invalid syntax

The original code is on that link and is the first part. I'm not using Junyper.

Anyone can help me?

the % pylab inline is a [jupyter magic method](https://ipython.readthedocs.io/en/stable/interactive/magics.html#magic-pylab). If you're not using jupyter, then you need to leave that out — G. Anderson, Apr 16 '20 at 18:06
related: [%precision 2 on Python](https://stackoverflow.com/q/50375504/674039) — wim, Apr 16 '20 at 18:11

wim · Accepted Answer · 2020-04-16T18:22:26.510

3

%pylab is an IPython magic for matplotlib. It's equivalent to this:

import numpy
import matplotlib
from matplotlib import pylab, mlab, pyplot
np = numpy
plt = pyplot

from IPython.display import display
from IPython.core.pylabtools import figsize, getfigs

from pylab import *
from numpy import *

The positional argument inline is specifying a matplotlib backend. Supported choices here depend on your platform and runtime (see matplotlib.rcsetup.all_backends for options).

If you're not using Jupyter notebooks, you can do the same in an IPython session. You'll need to have installed matplotlib in your Python environment.

edited Apr 16 '20 at 18:22

answered Apr 16 '20 at 18:14

wim

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Yes, I was. I tried to execute your suggestion, but the same error happens... – Marcelo João Apr 16 '20 at 18:20
It will run in **IPython**. It will not run in regular python unless you remove/replace the magic. – wim Apr 16 '20 at 18:21
As I said I'm not a programmer, I'm trying to use the code created to analyze data... I run the program in the Ubuntu terminal using the command: python3 code.py – Marcelo João Apr 16 '20 at 18:30
You can use `python3 -m IPython code.py`. Or just use jupyter notebooks. Or replace the magics in the source code. Up to you :) – wim Apr 16 '20 at 18:34

wjandrea · Answer 2 · 2020-04-16T18:26:16.863

1

You should run the program in Jupyter, or at least IPython. The % is IPython-specific syntax, and pylab is an IPython magic command for using matplotlib. Also note the file extension: .ipynb is a Jupyter notebook (formerly called IPython notebook), while a Python file would have a .py extension.

edited Apr 16 '20 at 18:26

answered Apr 16 '20 at 18:06

wjandrea

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Thanks for your reply. Is there no way to run without being in Junyper? – Marcelo João Apr 16 '20 at 18:12
2

It is not a Jupyter-specific extension. It is for matplotlib. – wim Apr 16 '20 at 18:13
@Marcelo *Jupyter. And I'm not really sure since I don't use Jupyter myself. – wjandrea Apr 16 '20 at 18:13
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@wim Thanks. How would you run matplotlib outside of Jupyter? Like if you ran it in IPython, would it open a popup with the image? – wjandrea Apr 16 '20 at 18:17
1

@wjandrea It would open a popup usually, yes. That is depending on the matplotlib backend that is configured, though. – wim Apr 16 '20 at 18:18
Yes, Jupyter*. Ok, nop. – Marcelo João Apr 16 '20 at 18:18
@wim Thanks! Edited to add. – wjandrea Apr 16 '20 at 18:26
@Marcelo You would need to run it in IPython at least. I edited to add. – wjandrea Apr 16 '20 at 18:27
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@wjandrea See screenshot in [Turning a Large Matrix into a Grayscale Image](https://stackoverflow.com/a/7696336/674039) for an example of what IPython using inline backend looks like (no popup). I think that was Qt4Agg backend (but it was some years ago and I don't use inline backend anymore). – wim Apr 16 '20 at 18:38

SyntaxError: invalid syntax - %pylab

2 Answers2