I have file input which is alphabetically sorted

Asburn 9
Ashley 10
Ashley 11
Bojourn 12

I want the output like

Asburn 9 
Ashley 21 
Bojourn 12 

Code I have used :

counts = defaultdict(int)
for line in sys.stdin:
 word, count  = line.split()
 counts[word]  = int(count)
  for wrd, count in counts.items():
     print("{}\t{}".format(wrd,count))

but I cannot used dictionary. How should I implement it

CodePudding user response：

With some help from Python's standard library:

from sys import stdin
from itertools import groupby
from operator import itemgetter

for word, group in groupby(map(str.split, stdin), itemgetter(0)):
    print(word, sum(int(count) for _, count in group))

Try it online!

CodePudding user response：

Try this:

prev_word = None
prev_count = 0
for line in sys.stdin:
    word, count  = line.split()
    count = int(count)
    if word != prev_word:
        if prev_word is not None:
            print(prev_word, str(prev_count))
        prev_count = count
        prev_word = word
    else:
        prev_count  = count
if prev_word != None:
    print(prev_word, prev_count)

Quick test: the following code returns the expected output

prev_word = None
prev_count = 0
for line in ['ashutosh 9', 'ashutosh 10', 'check 11', 'check 11', 'zebra 11']:
    word, count  = line.split()
    count = int(count)
    if word != prev_word:
        if prev_word is not None:
            print(prev_word, prev_count)
        prev_count = count
        prev_word = word
    else:
        prev_count  = count
if prev_word != None:
    print(prev_word, prev_count)

CodePudding user response：

Used a regex to list the key-value like terms, group them by the key, decouple the keys-values of each group with zip.

import re
import itertools as it

text = """Asburn 9
Ashley 10
Ashley 11
Bojourn 12"""

pairs = re.findall(r'^(. ?)\s(\d )\n*', text, re.M)

groups = [zip(*grp) for _, grp in it.groupby(pairs, lambda p: p[0])]

for keys, values in groups:
    print(keys[0], sum(map(int, values)))