Dictionary use instead of dynamic variable names in Python

Question

I have a long text file having truck configurations. In each line some properties of a truck is listed as a string. Each property has its own fixed width space in the string, su

Answer 1

Here's a complete solution from string to output:

from collections import namedtuple, defaultdict

# lightweight class
Truck = namedtuple('Truck', 'weights spacings')

def parse_truck(s):
    # convert to array of numbers
    numbers = [int(''.join(t)) for t in zip(s[::2], s[1::2])]

    # check length
    n = numbers[0]
    assert n * 2 == len(numbers)
    numbers = numbers[1:]

    return Truck(numbers[:n], numbers[n:])

trucks = [
    parse_truck("031028331004"),
    ...
]

# dictionary where every key contains a list by default
trucks_by_spacing = defaultdict(list)

for truck in trucks:
    # (True, False) instead of '10'
    key = tuple(space > 6 for space in truck.spacings)
    trucks_by_spacing[key].append(truck)

print trucks_by_spacing

print trucks_by_spacing[True, False]