python parse adjacency matrix from an input file

Question

I'm having a input .txt file with adjacency matrix looks like:

    A    B    C
A   0    55   0
B   55   0    0
C   0    0    0

How can I parse this input into a 2D array or nested dictionary?

e.g.

map['A']['B'] = 55

Answer 1

import StringIO

# this is just for the sake of a self-contained example
# this would be your actual file opened with open()
inf = StringIO.StringIO("    A    B    C\n"
        "A   0    55   0\n"
        "B   55   0    0\n"
        "C   0    0    0")

import re
map = {}
lines = inf.readlines()
headers = []

# extract each group of consecutive word characters. 
# If your headers might contain dashes or other non-word characters,
# you might want ([^\s]+) instead.
for header in re.findall('(\w+)', lines[0]):
    headers.append(header)
    map[header] = {}

for line in lines[1:]:
    items = re.findall('(\w+)', line)
    rowname = items[0]
    for idx, item in enumerate(items[1:]):
        map[headers[idx]][rowname] = item

print map