In `python`, I'm trying to format a number to be a fixed-length string with leading zeros, which can be done like so:

```
'{:0>10}'.format('10.0040')
'00010.0040'

```

I have a negative number and want to express the negative, I would get this:

```
'{:0>10}'.format('-10.0040')
'00-10.0040'

```

If I wanted to format the string to be:

```
'-0010.0040'

```

how could I do this? 

I could do an if/then, but wondering if format would handle this already.