cpython/Lib/test/test_pow.py
2002-04-01 19:01:39 +00:00

121 lines
3.8 KiB
Python

import sys
import test_support
def powtest(type):
if type != float:
print " Testing 2-argument pow() function..."
for i in range(-1000, 1000):
if pow(type(i), 0) != 1:
raise ValueError, 'pow('+str(i)+',0) != 1'
if pow(type(i), 1) != type(i):
raise ValueError, 'pow('+str(i)+',1) != '+str(i)
if pow(type(0), 1) != type(0):
raise ValueError, 'pow(0,'+str(i)+') != 0'
if pow(type(1), 1) != type(1):
raise ValueError, 'pow(1,'+str(i)+') != 1'
for i in range(-100, 100):
if pow(type(i), 3) != i*i*i:
raise ValueError, 'pow('+str(i)+',3) != '+str(i*i*i)
pow2 = 1
for i in range(0,31):
if pow(2, i) != pow2:
raise ValueError, 'pow(2,'+str(i)+') != '+str(pow2)
if i != 30 : pow2 = pow2*2
for othertype in int, long:
for i in range(-10, 0) + range(1, 10):
ii = type(i)
for j in range(1, 11):
jj = -othertype(j)
try:
pow(ii, jj)
except ValueError:
raise ValueError, "pow(%s, %s) failed" % (ii, jj)
for othertype in int, long, float:
for i in range(1, 100):
zero = type(0)
exp = -othertype(i/10.0)
if exp == 0:
continue
try:
pow(zero, exp)
except ZeroDivisionError:
pass # taking zero to any negative exponent should fail
else:
raise ValueError, "pow(%s, %s) did not fail" % (zero, exp)
print " Testing 3-argument pow() function..."
il, ih = -20, 20
jl, jh = -5, 5
kl, kh = -10, 10
compare = cmp
if type == float:
il = 1
compare = test_support.fcmp
elif type == int:
jl = 0
elif type == long:
jl, jh = 0, 15
for i in range(il, ih+1):
for j in range(jl, jh+1):
for k in range(kl, kh+1):
if k != 0:
if type == float or j < 0:
try:
pow(type(i),j,k)
except TypeError:
pass
else:
raise ValueError, "expected TypeError from " + \
"pow%r" % ((type(i), j, k),)
continue
if compare(pow(type(i),j,k), pow(type(i),j)% type(k)):
raise ValueError, "pow(" +str(i)+ "," +str(j)+ \
"," +str(k)+ ") != pow(" +str(i)+ "," + \
str(j)+ ") % " +str(k)
print 'Testing integer mode...'
powtest(int)
print 'Testing long integer mode...'
powtest(long)
print 'Testing floating point mode...'
powtest(float)
# Other tests-- not very systematic
print 'The number in both columns should match.'
print `pow(3,3) % 8`, `pow(3,3,8)`
print `pow(3,3) % -8`, `pow(3,3,-8)`
print `pow(3,2) % -2`, `pow(3,2,-2)`
print `pow(-3,3) % 8`, `pow(-3,3,8)`
print `pow(-3,3) % -8`, `pow(-3,3,-8)`
print `pow(5,2) % -8`, `pow(5,2,-8)`
print
print `pow(3L,3L) % 8`, `pow(3L,3L,8)`
print `pow(3L,3L) % -8`, `pow(3L,3L,-8)`
print `pow(3L,2) % -2`, `pow(3L,2,-2)`
print `pow(-3L,3L) % 8`, `pow(-3L,3L,8)`
print `pow(-3L,3L) % -8`, `pow(-3L,3L,-8)`
print `pow(5L,2) % -8`, `pow(5L,2,-8)`
print
print
for i in range(-10, 11):
for j in range(0, 6):
for k in range(-7, 11):
if j >= 0 and k != 0:
o = pow(i,j) % k
n = pow(i,j,k)
if o != n: print 'Integer mismatch:', i,j,k
if j >= 0 and k != 0:
o = pow(long(i),j) % k
n = pow(long(i),j,k)
if o != n: print 'Integer mismatch:', i,j,k