Dictionary count based on sub-string

Question

I am trying to open a file, iterate over each line, and do a count of a specific word in each line to add to a Dictionary.

For the sake of this question, the file has values in it that look like this:

From some.email@address.ac.za Sat Jan  5 09:14:16 2008
From some.email@address.ac.za Sat Jan  5 09:14:16 2008
From some.email@address.ac.za Fri Jan  5 09:14:16 2008
From some.email@address.ac.za Wed Jan  5 09:14:16 2008
From some.email@address.ac.za Tue Jan  5 09:14:16 2008
From some.email@address.ac.za Sat Jan  5 09:14:16 2008
From some.email@address.ac.za Sat Jan  5 09:14:16 2008
From some.email@address.ac.za Sat Jan  5 09:14:16 2008

What I want to do is read in the file, iterate over each line, and keep a count of the days of the week and return that in a Dictionary. So the results would look something like this:

{'Sat': 5, 'Fri': 1, 'Wed': 1, 'Tue': 1}

I have it to the point of reading in the file and splitting at the whitespace, and appending to a list. After that I am stuck and can't drill down to that specific section of test in each list.

Any ideas?

fname = input('Enter the file name: ')
try:
    fhand = open(fname)
except:
    print('File cannot be opened:', fname)
    exit()

counts = dict()
l1 = []
for line in fhand:
    line = line.split()
    l1.append(line)
for date in l1:
    for day in date:
        if day[2] not in counts:
            counts[day] = 1
        else:
            counts[day] += 1

taurus05 · Accepted Answer · 2019-01-31T19:10:04.327

2

from collections import defaultdict
fname = input('Enter the file name: ')
try:
    fhand = open(fname)
except:
    print('File cannot be opened:', fname)
    exit()

counts = defaultdict(int)
l1 = []
for line in fhand:
    line = line.split()
    for word in line:
        if word in ['Sun', 'Mon', 'Tue', 'Wed', 'Thrus', 'Fri', 'Sat']:
            counts[word] += 1
print(counts)

After reading each line and splitting it into words, you can check if the word is a day name, and if it is, then update the value corresponding to that day.

edited Jan 31 '19 at 19:10

answered Jan 31 '19 at 19:07

taurus05

2,491
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28

what does defaultdict do? – Maria Nazari Jan 31 '19 at 19:09
Check documentation here -> https://docs.python.org/2/library/collections.html – taurus05 Jan 31 '19 at 19:10
1

oh that is much simpler isn't it, rather than trying to slice to find the day of the week. Thanks. Ill accept once I am able to – JD2775 Jan 31 '19 at 19:12
2

@MariaNazari a defaultdict provides that an unknown key will not raise a KeyError. Instead, it returns a default value. – hd1 Jan 31 '19 at 19:14

Dictionary count based on sub-string

1 Answers1