#!/usr/local/bin/python3.10
# Source: https://perlmonks.org/index.pl?node_id=11148702
#
# This is one Python implementation based on the problem specification
+ ...
#
#   Rosetta Code: Long List is Long, 20221130,
#   by eyepopslikeamosquito
#   https://perlmonks.org/?node_id=11148465


import sys
from collections import defaultdict
from hashlib import sha256
from pathlib import PosixPath
from timeit import default_timer


# Takes ~0.3 s.
def verify( output :str,
            # The digest of the output produced from eyepopslikeamosqu
+ito's
            # program, "gen-llil.pl", after generating 3 input files. 
+Update it
            # as needed.
            expected_sum :str =
               '70a1644743e9b9d8d73094ed1826527f27a7f3f131c3f28a63aaeb
+85e1af8fef'
         ) ->None:
   """
   Prints a message about output being different than expected.

   Args:
      output      : Stringified output of sorted input.
      expected_sum: SHA-256 digest sum in hexadecimal of expected ASCI
+I output.
   """
   # Need to encode the resulting string with encoding of "ascii" to m
+atch up
   # of the input.
   # Also make sure that each category-count pair ends with a newline.
   sum = sha256( output.encode( encoding = 'ascii' ) ).hexdigest()
   if sum != expected_sum:
      sys.stderr.write( f"OUTPUT is DIFFERENT!\n  {sum}\n" )
   return


# Takes ~7-11 s.
def sort_val_desc_key_asc( cat_count :dict[ str, int ] ) ->list[ str ]
+:
   """
   Returns:
      A `list` of sorted keys by decreasing order of values & increasi
+ng order of
      keys.

   Args:
      cat_count: A `dict` with string key & integer value.
   """
   once = sorted( cat_count.keys() )
   return sorted( once, key = lambda k: cat_count[ k ], reverse = True
+ )


# Takes ~12-16 s.
def collect( data_list :list ) ->dict[ str, int ]:
   """
   Returns:
      A `dict` with category as key & total count as value.

   Args:
      data_list: list of file paths as `pathlib.PosixPath` objects.

   Side effect:
      Updates `time_stat` with the time taken to collect the data.
   """
   cat_count = defaultdict( lambda: 0 )

   delimiter = '\t'
   open_prop = { 'mode' : 'rt',
                  'encoding' : 'ascii',
                  'newline' : '\n'
               }
   for path in data_list:
      with path.open( **open_prop ) as fh:
         for line in fh:
            category, number = line.split( delimiter, 1 )
            cat_count[ category ] += int( number )

   return cat_count


# Collect file paths.
if sys.argv[1:]:
   data_list = [ PosixPath( p ) for p in sys.argv[1:] ]
else:
   sys.exit( 'Give a file list with data to process' )


start = default_timer()

# Process.
cat_count = collect( data_list )
end_collect = default_timer()

# Sort.
sorted_key = sort_val_desc_key_asc( cat_count )
end_sort = default_timer()
# Format; take ~7 s.
stringified = ''.join( f'{k}\t{cat_count[ k ]}\n' for k in sorted_key 
+)
end_stringification = default_timer()

# Either verify or print to verifiy outside of the program.
# Verification is slightly slower than dumping string on standard outp
+ut.
verify_or_print = 'NOT verify'
if verify_or_print == 'verify':
   output_label = 'sha256 verification'
   verify( stringified )
else:
   output_label = 'output'
   print( stringified, end = '' )

end = default_timer()

# Print time taken.
stat = { 'collect' : end_collect - start,
         'sort'    : end_sort - end_collect,
         'stringification' : end_stringification - end_sort,
         output_label      : end - end_stringification,
         # ~28-36 s.
         'total' : end - start
      }

max_label_width = max( len( k ) for k in stat.keys() )
#
decimal_place = 1
max_time_width = max( len( f'{t:0.{decimal_place}f}' ) for t in stat.v
+alues() )
time_format = f'{max_time_width}.{decimal_place}f'
#
out_format = '{label:{label_pad}}: {time:{time_format}} s\n'
#
sys.stderr.write( f'# {__file__}\n' )
for step, time in stat.items():
   mess = out_format.format( label = step, label_pad = max_label_width
+,
                             time = time, time_format = time_format
                           )
   sys.stderr.write( mess )
[download]

# parv-20221210-two-sorts.py
collect        : 15.9 s
sort           :  7.8 s
stringification:  7.5 s
output         :  0.1 s
total          : 31.3 s
[download]