Question

I created a dictionary of lists using:

names = defaultdict(list)

I am reading a line from the text file, splitting it into 3 columns. I am making the first column of the line as key and other two columns as the values in a list. I used the following code segment as following:

with open('f.txt') as f:
    lines = [l.split() for l in f.readlines() if l.strip()]
    for l in lines:
            names[l[0]].append([l[1],l[2]])

I have the text files like this:

00:12:34:23:45:67       134     123.456

45:34:23:45:44:23       133     345.123

3f:32:dr:45:34:r5       133     212.345

00:12:34:23:45:67       134     555.555

00:12:34:23:45:67       136     555.556

00:12:34:23:45:67       134     555.560

If i run my program to output key:value pairs, the output is:

00:12:34:23:45:67 [['134', '123.456'], ['134', '555.555'], ['136', '555.556'], ['134', '555.560']]

45:34:23:45:44:23 [['133', '345.123']]

3f:32:dr:45:34:r5 [['133', '212.345']]

How can I access the individual elements of the list? For example, in this output, I want to count number of 133, 134, 135, 136 of each key and the time difference between each type. For example, for the key 00:12:34:23:45:67, there are 3 134’s, 1 136. The time difference between highest of and lowest of 134’s for that key is 555.560-123.456. I want this result for all 133,134,135,136 types. I am struggling for this problem from many days. please help. Much appreciated.

Answer 1

It seems like a better data structure is in order here…

from collections import defaultdict
names=defaultdict(lambda :defaultdict(list))

with open('f.txt') as f:
   lines = [l.split() for l in f.readlines() if l.strip()]
   for l in lines:
       names[l[0]][l[1]].append(float(l[2]))

Now, to get the counts and differences from max/min:

for k,v in names.items():
    for kk,vv in v.items():
        print k,kk,len(vv),max(vv)-min(vv)

Output:

00:12:34:23:45:67 136 1 0.0
00:12:34:23:45:67 134 3 432.104
45:34:23:45:44:23 133 1 0.0
3f:32:dr:45:34:r5 133 1 0.0