Thread: help with some basic python

i'm relatively new python , haven't got hang of yet. below function code have been writing. snagged on problem ii can't fathom remedy , hoping guide me how might negate issue.
context of code calculator of % frequency of values. "distro" large dictionary of integers , frequencies.

output insists "data" object created nonetype.
nonetype? why there 1 here? can around them?

php code:

def print_stats(distro):
    l = distro['total']
    del distro['total']
    data = [(v, k) for k, v in distro.items()]
    data = sorted(data)
    data = data.reverse()
    data = data[:10] # this returns nonetype is not subscriptable

    names=[]; numbers=[]
    for k, v in data:  # this returns nonetype is not iterable
        names.append(str(int(v)).center(8))
        numbers.append(k)

    for x in range(len(numbers)):
        z = (numbers[x]/l)*100    
        z = str(round(z, 2))
        z = z +"%"
        numbers[x] = z.center(7) 


thankyou

posted beauxesprits13

php code:

def print_stats(distro):
    l = distro['total']
    del distro['total']
    data = [(v, k) for k, v in distro.items()]
    data = sorted(data)
    data = data.reverse()
    data = data[:10] # this returns nonetype is not subscriptable

    names=[]; numbers=[]
    for k, v in data:  # this returns nonetype is not iterable
        names.append(str(int(v)).center(8))
        numbers.append(k)

    for x in range(len(numbers)):
        z = (numbers[x]/l)*100    
        z = str(round(z, 2))
        z = z +"%"
        numbers[x] = z.center(7) 


the problem line:

code:

data = data.reverse()

the reverse method works "in place" or "destructively", meaning modifies original list forever. makes unnecessary return reversed list, because data reversed list.

<rant>
yes, me, comes lisp used lisp , functional programming, having destructive list reversal function makes me mad. there should functional, non-destructive version worked wanted.
</rant>

nonetype come from? well, data.reverse doesn't return anything, data becomes none... none python's way has no value nor type , it's when value function returns nothing.

so, don't reassign data @ line. data.reverse() , that's it.

edit: reason, wrote came lisp. no, that's not true: learned lisp after learning python. corrected, factual accuracy

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