Map/Reduce : Answer to exercise 1
from functools import reduce
from multiprocessing import Pool
Function that returns the number of lines
of text in the file 'filename'
with open(filename) as f:
def print_result(filename, nlines):
"""Function to print out the number of lines"""
print("%s contains %s lines" % (filename, nlines))
if __name__ == "__main__":
# get all of the names of the plays from the command line
filenames = sys.argv[1:]
with Pool() as pool:
# map the count_lines function against all of the
# files listed in "filenames"
play_line_count = pool.map(count_lines_in_file, filenames)
# now print out the results (can also be a map)
pool.starmap(print_result, zip(filenames, play_line_count))
total = reduce(lambda x, y: x + y, play_line_count)
print("The total number of lines is %s." % total)