Lib/test/test_pow.py

   1 import sys
   2 import test_support
   3
   4 def powtest(type):
   5     if (type!=float):
   6         print "    Testing 2-argument pow() function..."
   7         for i in range(-1000, 1000):
   8             if (pow(type(i),0)!=1):
   9                 raise ValueError, 'pow('+str(i)+',0) != 1'
  10             if (pow(type(i),1)!=type(i)):
  11                 raise ValueError, 'pow('+str(i)+',1) != '+str(i)
  12             if (pow(type(0),1)!=type(0)):
  13                 raise ValueError, 'pow(0,'+str(i)+') != 0'
  14             if (pow(type(1),1)!=type(1)):
  15                 raise ValueError, 'pow(1,'+str(i)+') != 1'
  16
  17         for i in range(-100, 100):
  18             if (pow(type(i),3)!=i*i*i):
  19                 raise ValueError, 'pow('+str(i)+',3) != '+str(i*i*i)
  20
  21         pow2=1
  22         for i in range(0,31):
  23             if (pow(2,i)!=pow2):
  24                 raise ValueError, 'pow(2,'+str(i)+') != '+str(pow2)
  25             if (i!=30): pow2=pow2*2
  26
  27     print "    Testing 3-argument pow() function..."
  28     il, ih = -20, 20
  29     jl, jh = -5,   5
  30     kl, kh = -10, 10
  31     compare = cmp
  32     if (type==float):
  33         il=1
  34         compare = test_support.fcmp
  35     elif (type==int):
  36         jl=0
  37     elif (type==long):
  38         jl,jh = 0, 15
  39     for i in range(il, ih+1):
  40          for j in range(jl,jh+1):
  41              for k in range(kl, kh+1):
  42                  if (k!=0):
  43                      if compare(pow(type(i),j,k), pow(type(i),j)% type(k)):
  44                          raise ValueError, "pow(" +str(i)+ "," +str(j)+ \
  45                               "," +str(k)+ ") != pow(" +str(i)+ "," + \
  46                               str(j)+ ") % " +str(k)
  47
  48
  49 print 'Testing integer mode...'
  50 powtest(int)
  51 print 'Testing long integer mode...'
  52 powtest(long)
  53 print 'Testing floating point mode...'
  54 powtest(float)
  55
  56 # Other tests-- not very systematic
  57
  58 print 'The number in both columns should match.'
  59 print `pow(3,3) % 8`, `pow(3,3,8)`
  60 print `pow(3,3) % -8`, `pow(3,3,-8)`
  61 print `pow(3,2) % -2`, `pow(3,2,-2)`
  62 print `pow(-3,3) % 8`, `pow(-3,3,8)`
  63 print `pow(-3,3) % -8`, `pow(-3,3,-8)`
  64 print `pow(5,2) % -8`, `pow(5,2,-8)`
  65 print
  66
  67 print `pow(3L,3L) % 8`, `pow(3L,3L,8)`
  68 print `pow(3L,3L) % -8`, `pow(3L,3L,-8)`
  69 print `pow(3L,2) % -2`, `pow(3L,2,-2)`
  70 print `pow(-3L,3L) % 8`, `pow(-3L,3L,8)`
  71 print `pow(-3L,3L) % -8`, `pow(-3L,3L,-8)`
  72 print `pow(5L,2) % -8`, `pow(5L,2,-8)`
  73 print
  74
  75 print pow(3.0,3.0) % 8, pow(3.0,3.0,8)
  76 print pow(3.0,3.0) % -8, pow(3.0,3.0,-8)
  77 print pow(3.0,2) % -2, pow(3.0,2,-2)
  78 print pow(5.0,2) % -8, pow(5.0,2,-8)
  79 print
  80
  81 for i in range(-10, 11):
  82  for j in range(0, 6):
  83   for k in range(-7, 11):
  84    if (j>=0 and k!=0):
  85     o=pow(i,j) % k
  86     n=pow(i,j,k)
  87     if (o!=n): print 'Integer mismatch:', i,j,k
  88    if (j>=0 and k<>0):
  89     o=pow(long(i),j) % k
  90     n=pow(long(i),j,k)
  91     if (o!=n): print 'Long mismatch:', i,j,k
  92    if (i>=0 and k<>0):
  93      o=pow(float(i),j) % k
  94      n=pow(float(i),j,k)
  95      if (o!=n): print 'Float mismatch:', i,j,k