Add item to a list in a dict - list

Question

I have a program that works as intended:
import os
import hashlib
from pprint import pprint
def md5(fname):
hash_md5 = hashlib.md5()
with open(fname, "rb") as f:
for chunk in iter(lambda: f.read(4096), b""):
hash_md5.update(chunk)
return hash_md5.hexdigest()
lst = []
for dirpath, dirnames, filenames in os.walk('d:\\python\\exercism.io'):
d = {dirpath: filenames}
for filename in filenames:
d[filename] = [os.stat(dirpath).st_mtime, md5(dirpath + '\\' + filename)]
# d[filename] = [os.stat(dirpath).st_mtime]
# d[filename] = [md5(dirpath + '\\' + filename)]
lst.append(d)
pprint(lst)
My question is this:
If I get rid of this line:
d[filename] = [os.stat(dirpath).st_mtime, md5(dirpath + '\\' + filename)]
and try to use the two commented out lines (with a modification -- see below) it fails.
1) Either commented out line works by themselves. I get a key: value pair in which the value is a list.
I then want to add the value of the second commented out line to the list.
I was trying this:
d[filename][1] = md5(dirpath + '\\' + filename)
but I get an index out of range error. The first element of the list
should be item [0], the second should be [1].
Partial output:
[{'ceasar_cipher.py': [1512494094.5630972, '844e069c90ebdb3e1e5f5dd56da2ac2e'],
'd:\\python\\exercism.io': ['ceasar_cipher.py',
'difference_of_squares.py',
'gigasecond.py',
'grains_in_python.py',
'hamming-compare.py',
'isogram.py',
'leap_year.py',
'rna_transcription.py',
'run_length_encoding.py'],
Note the key: 'ceasar_cipher.py' has a value which is a two element list.
I want to construct the exact same output with the two commented out lines
versus the single line I am using now (just so I can, not that I should). My concern is simply what am I doing wrong.

Answer 1

You need to append to your list:
d[filename] = [os.stat(dirpath).st_mtime]
d[filename].append(md5(dirpath + '\\' + filename))
to get the same effect. There is no item at index 1 yet. You need to create it, for example with append().