% syntax in Python

Question

I was working on a project in which I had to write

%matplotlib inline 

at the beginning to solve a problem.

But I'm wondering what does this "%" stands for: is it an operator ? Has it a name so I could do some researches about it ?

Answer 1

You are not looking at standard Python code.

You are almost certainly using an IPython interactive session, and it uses % as a prefix to recognize special commands, called magic functions. Type %quickref to get a quick reference. From that reference:

%magic : Information about IPython's 'magic' % functions.

Magic functions are prefixed by % or %%, and typically take their arguments without parentheses, quotes or even commas for convenience. Line magics take a single % and cell magics are prefixed with two %%.

If you then type in %magic you'll find the reference documentation for available magic functions, including:

%matplotlib:

 %matplotlib [gui]

Set up matplotlib to work interactively.

This function lets you activate matplotlib interactive support at any point during an IPython session. It does not import anything into the interactive namespace.