How can I define a function - say, `def polyToString(poly)` - to return a string containing the polynomial `poly` in standard form?

For example: the polynomial represented by `[-1, 2, -3, 4, -5]` would be returned as:

```
"-5x**4 + 4x**3 -3x**2 + 2x**1 - 1x**0"

```

```
def polyToString(poly):
    standard_form=''
    n=len(poly) - 1
    while n >=0:
        if poly[n]>=0:
            if n==len(poly)-1: 
                standard_form= standard_form + '   '+ str(poly[n]) + 'x**%d'%n 
            else:
                standard_form= standard_form + ' + '+str(poly[n]) + 'x**%d'%n
        else:
            standard_form= standard_form + ' - ' + str(abs(poly[n])) + 'x**' + str(n)
        n=n-1
    return standard_form

```