Decode ascii and reversed words sentence

Use lambdas

def f(a,b):return c

can be shortened to

f=lambda a,b:c

(the f= can also be removed per CGCC site standards)

Remove excess []s

x.join([a for b in c])

can be

x.join(a for b in c)

since join can take a generator instead of a list

Split is on spaces by default

Thanks ElPedro for reminding me about this

So the split(' ')s can be shortened, which in turn means the s=' ' doesn't help (and it only broke even in the first place).

Take input from STDIN and output to STDOUT

print will automatically print arguments with space as a separator if you use * to unpacks the sequence/collection into positional arguments, and taking input via input() is shorter. Also, setting s to space doesn't actually save any bytes.

Altogether, this is 79 bytes:

print(*[w[::-1]for w in(''.join(chr(int(c))for c in input().split()).split())])

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or, if you're dedicated to having a function, 82 bytes:

lambda m:' '.join(w[::-1]for w in(''.join(chr(int(c))for c in m.split()).split()))

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plus seven or so characters if you really need the function to be called decode

Python 2, 78 bytes

lambda m:' '.join(x[::-1]for x in''.join(map(chr,map(int,m.split()))).split())

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Edit changed to a Python 2 answer as the lambda is shorter than the print/input version in Python 2.

This uses a couple of maps to get the list of characters which we then join on "", split again on space, reverse each element then rejoin again on space for 78. Also works in Python 3.

Just a pity that it needs so many brackets :-(

Python 3, 75 bytes

lambda a:' '.join(''.join(map(chr,map(int,a.split())))[::-1].split()[::-1])

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Python 3, 70 bytes

If taking input from STDIN and outputing to STDOUT is fine then it takes only 70 bytes this is mostly because the spread operator (*) is shorter than ' '.join()

print(*''.join(map(chr,map(int,input().split())))[::-1].split()[::-1])

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