Find the largest file of given extension in a directory

largest_file.py

#!/usr/bin/python
import os, sys

if len(sys.argv)==1 :
    folder='.'
else :
    folder=sys.argv[1]


if len(sys.argv)==3 :
    extention=sys.argv[2]
else :
    extention='py'


filez=os.listdir(folder)
pfiles=[]
for fil in filez :
    if fil.endswith(extention) :
        pfiles.append(fil)
print '\n Files matching extension \n'
print pfiles
fil_size=[]
for pfil in pfiles :
    fpath=os.path.join(folder,pfil)
    fsize=os.path.getsize(fpath)
    fil_size.append((pfil,fsize))

def getfilsiz(tupl):
    return tupl[1]
sorted_fil=sorted(fil_size,key=getfilsiz)
print ('\n = = = = = = \n')
print 'Largest file : ', sorted_fil[-1][0]
if sorted_fil[-1][1] > 1048576:
    print 'Size : ', sorted_fil[-1][1]/1048576,'MB'

elif sorted_fil[-1][1] >1024 :
    print 'Size : ', sorted_fil[-1][1]/1024 ,'KB'

else :
    print 'Largest file : ', sorted_fil[-1][1],'Bytes'

print ' '