Issue saving a matplotlib figure

Question

I am trying to save a figure. Something quite simple.

The program that makes the plots receives a list called "data"

data['Reading [V/dec]','OK values', 'Defects', 'Valids', 'Non valids']

fig.savefig(data[0]+'.png')

If I use the code above, the figure is just not saved.

If I do like this:

data['Reading [V per dec]','OK values', 'Defects', 'Valids', 'Non valids']

fig.savefig(data[0]+'.png')

The figure is saved.

So I am wondering why I cannot use 'Reading [V/dec]' as a name for my .png file. And how to make it take the name as it is 'Reading [V/dec]'.

Just one more comment, according to an aswer I got, I have to say that I am using Windows.

Answer 1

This is nothing to do with matplotlib really, and is instead because of how operating systems handle directories. / is often used for separating directories, i.e. my file is stored here /path/to/my/file.py. As such, it is unlikely that you're allowed to use the symbol / in a filename as it would confuse matters far too much.

This is definitely not allowed in Windows and Ubuntu, not sure about OS X or other Linux distros but I suspect it is not allowed for all.