mapper.py

#!/usr/bin/python

# The Mapper
import sys
import csv

# Set local variables
iteration = 0

currentCountry = None
previousCountry = None
currentFx = None
previousFx = None
percentChange = None
currentKey = None

fxMap = []

# print "Starting mapper.py"

infile = sys.stdin

next(infile) # skip first line of input file

for line in infile:

    line = line.strip()
    line = line.split(',', 2)

    try:
        # Get data from line
        currentCountry = line[1].rstrip()
        if len(line[2]) == 0:
            continue
        currentFx = float(line[2])

        if currentCountry != previousCountry:
            previousCountry = currentCountry
            previousFx = currentFx
            previousLine = line
            continue

        # If country same as previous, add to map
        elif currentCountry == previousCountry:
            percentChange = ((currentFx - previousFx) / previousFx) * 100.00
            percentChange = round(percentChange, 2)
            percentChange = percentChange

            currentKey = "%s: %6.2f%%" % (currentCountry, percentChange)

            # Set the array with tuple keys
            fxMap.append(tuple([currentKey, 1]))

        # Update Values
        previousCountry = currentCountry
        previousFx = currentFx
        previousLine = line

        # Uncomment if you want to see the output
#         if iteration % 50000 == 0:
#             print "Current iteration is %d" % iteration
#         iteration += 1

    # Handle unexpected errors
    except Exception as e:
        template = "An exception of type {0} occurred. Arguments:\n{1!r}"
        message = template.format(type(e).__name__, e.args)
        print "currentFx: %.2f previousFx: %.2f" % (currentFx, previousFx)
        print message
        sys.exit(0)

#
# print "mapper.py has completed with %d iterations" % (iteration - 1)

# Show the returned values
for i in sorted(fxMap):
    print "%-20s - %d" % (i[0], i[1])