Makes numpy arange ranges from the shell, even chain together with commas

arange.py

#!/usr/bin/env python

import numpy
import sys

if len(sys.argv) < 4:
	print( "Usage: arange start stop step [, ndecimals]" )
	exit()

if not sys.stdin.isatty():
	for line in sys.stdin:
		sys.stdout.write(line.strip())

start = float(sys.argv[1])
stop  = float(sys.argv[2])
step  = float(sys.argv[3])
ndigits = 2;

if len( sys.argv ) > 4:
	ndigits = sys.argv[4]

vals = ""
fmt = "%0." + str(ndigits) + "f"
for v in numpy.arange( start, stop, step ):
	vals = vals + fmt % v + ", "

if not sys.stdin.isatty() :
	print(", " + vals[:-2])
else :
	print(vals[:-2])

usage.sh

#Usage Example:
$> arange 0 3 0.1 1 | arange  3 4 0.1 1
0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9