fast inplace pandas sorting

# https://github.com/pandas-dev/pandas/issues/15389

import pandas
import numpy
import resource
import sys

variant, nrows, ncols = sys.argv[1:4]

numpy.random.seed(0)
df = pandas.DataFrame(numpy.random.randn(int(nrows), int(ncols)))

if variant == '1':
        df.sort_values(by=list(df.columns), inplace=True)
elif variant == '2':
        order = numpy.lexsort(
                [df[col].values for col in reversed(list(df.columns))])
        for col in list(df.columns):
                df[col] = df[col].values[order]

usage = resource.getrusage(resource.RUSAGE_SELF)
print 'Time:', usage.ru_utime
print 'Memory:', usage.ru_maxrss
print 'Result hash:', hash(df.values.tobytes())