csv-filter

#!python
import csv
import fileinput
import sys
import getopt

helpMessage=(
        "Usage csv-filter -[GLEOAaDdcn] [INPUT_FILE]\n"
        "\n"
        "-c n    Column to check\n"
        "-G n    Value must be greater than n.\n"
        "-L n    Value must be less that n.\n"
        "-E n    Value must be equal to n.\n"
        "-A      Strongly acending.\n"
        "-a n    Ascending with a tolerance of n.\n"
        "-D      Strongly descending.\n"
        "-d n    Descending with a tolerance of n.\n"
        "-O      Handle conditions as disjunction.\n"
        "-K n    Skip first n lines."
)


upperLimit = None
lowerLimit = None
equalValue = None
ascTolerance = None
descTolerance = None
col = 0
disjunct = False
skip = 0

prevLine = None

def main(argv):
	global upperLimit
	global lowerLimit
	global col
	global equalValue
	global disjunct
	global skip
	global ascTolerance
	global descTolerance
	
	global prevLine
	
	hexMode = False
	
	upperLimitStr = None
	lowerLimitStr = None
	ascToleranceStr = None
	descToleranceStr = None
	
	optlist, args = getopt.getopt(argv, 'G:L:E:Oc:K:hAa:Dd:HC')
	for opt in optlist:
		if opt[0] == '-L':
			upperLimitStr = opt[1]
		elif opt[0] == '-G':
			lowerLimitStr = opt[1]
		elif opt[0] == '-c':
			col = int(opt[1])-1
		elif opt[0] == '-E':
			equalValue = opt[1]
		elif opt[0] == "-O":
			disjunct = True
		elif opt[0] == "-K":
			skipStr = int(opt[1])
		elif opt[0] == "-D":
			descToleranceStr = "-1"
		elif opt[0] == "-d":
			descToleranceStr = opt[1]
		elif opt[0] == "-A":
			ascToleranceStr = "-1"
		elif opt[0] == "-a":
			ascToleranceStr = opt[1]
		elif opt[0] == "-C":
			# Constant
			ascToleranceStr = "0"
			descToleranceStr = "0"
		else:
			print(helpMessage)
			exit(1)
	
	# Convert opt strings to values
	if hexMode:
		upperLimit = int(upperLimitStr, 16)
		lowerLimit = int(lowerLimitStr, 16)
		ascTolerance  = int(ascToleranceStr, 16)
		descTolerance = int(descToleranceStr, 16)
	else:
		upperLimit = float(upperLimitStr) if upperLimitStr else 0
		lowerLimit = float(lowerLimitStr) if lowerLimitStr else 0
		ascTolerance  = float(ascToleranceStr) if ascToleranceStr else 0
		descTolerance = float(descToleranceStr) if descToleranceStr else 0
	
	source = fileinput.input(args[0]) if len(args) else sys.stdin
	for line in source:
		if skip > 0:
			skip -= 1
			continue
		fields=list(csv.reader([line]))[0]
		if check(fields):
			print(line, end='')
		prevLine = line

def check(fields):
	global upperLimit
	global lowerLimit
	global col
	global equalValue
	global disjunct
	global ascTolerance
	global descTolerance
	global prevLine
	
	if disjunct:
		if (upperLimit and upperLimit > float(fields[col])):
			return True
		if (lowerLimit and lowerLimit < float(fields[col])):
			return True
		if (equalValue and equalValue == fields[col]):
			return True
		return False
	else:
		if upperLimit and not upperLimit > float(fields[col]):
			return False
		if lowerLimit and not lowerLimit < float(fields[col]):
			return False
		if equalValue and not equalValue == fields[col]:
			return False
		if ascTolerance:
			if ascTolerance == -1 and prevLine[col] <= float(fields[col]):
				return False
			elif prevLine[col] < float(fields[col]) + ascTolerance:
				return False
		if descTolerance:
			if descTolerance == -1 and prevLine[col] >= float(fields[col]):
				return False
			elif prevLine[col] > float(fields[col]) - descTolerance:
				return False
	return True

if __name__ == "__main__":
	main(sys.argv[1:])