I've just joined two arrays of unequal length together with the command:

```
allorders = map(None,todayorders, lastyearorders)

```

where "none" is given where today orders fails to have a value (as the todayorders array is not as long).

However, when I try to pass the allorders array into a matplotlib bar chart:

```
 p10= plt.bar(ind, allorders[9],   width, color='#0000DD', bottom=allorders[8])

```

..I get the following error:

```
TypeError: unsupported operand type(s) for +=: 'int' and 'NoneType'

```

So, is there a way for matplotlib to accept none datatypes? if not, how do I replace the 'Nones' with zeroes in my allorders array?

If you can, as I am a Python newbie (coming over from the R community), please provide detailed code from start to finish that I can use/test.