Files
pyfa/util.py
2010-09-05 14:26:08 +04:00

63 lines
2.6 KiB
Python

def shorten(val, prec=4, lowest=0, highest=0):
"""
Add suffix to value, transform value to match new suffix and round it.
Keyword arguments:
val -- value to process
prec -- precision of final number (number of significant positions to show)
lowest -- lowest order for suffixizing
highest -- highest order for suffixizing
Suffixes below lowest and above highest orders won't be used.
"""
# Take numbers only matching/above lowest possible positive suffix
if abs(val) >= 1000 and highest >= 3:
suffixmap = {3 : "k", 6 : "M", 9 : "G"}
# Start from highest possible suffix
for key in sorted(suffixmap, reverse = True):
# Find first suitable suffix and check if it's not above highest order
if val >= 10**key and key <= highest:
return u"{0}{1}".format(process(val/float(10**key), prec), suffixmap[key])
# Take numbers between 0 and 1, and matching/below highest possible negative suffix
elif abs(val) < 1 and val != 0 and lowest <= -3:
suffixmap = {-6 : u'\u03bc', -3 : "m"}
# Start from lowest possible suffix
for key in sorted(suffixmap, reverse = False):
# Check if mantissa with next suffix is in range [1, 1000)
# Here we assume that each next order is greater than previous by 3
if val < 10**(key+3) and key >= lowest:
return u"{0}{1}".format(process(val/float(10**key), prec), suffixmap[key])
# No suitable suffixes are found withing given order borders, or value
# is already within [1, 1000) boundaries, just return rounded value with no suffix
else:
return u"{0}".format(process(val, prec))
def process(val, prec):
"""
Round number.
Keyword arguments:
val -- value to round
prec -- precision of final number (number of significant positions to show)
Integer numbers are not rounded, only fractional part.
"""
# Check if we have no integer and some fraction after bunch of zeroes,
# counting these zeros in process
shiftFraction, integersNumber = 0, 0
if int(val) == 0 and val != 0:
while val < 0.1**(shiftFraction+1):
shiftFraction += 1
else:
while abs(val) >= 10**(integersNumber):
integersNumber +=1
# We want to show at least (prec) significant numbers in any cases
roundFactor = prec + shiftFraction - integersNumber
# But we don't want to round integers
if roundFactor < 0: roundFactor = 0
val = round(val, roundFactor)
# Strip trailing zero for integers and convert to string
result = str(val)[-2:] == '.0' and str(val)[:-2] or str(val)
return result