def num_in_base(val, base, min_digits=1, complement=False,
digits="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"):
"""Convert number to string in specified base
If minimum number of digits is specified, pads result to at least
that length.
If complement is True, prints negative numbers in complement
format based on the specified number of digits.
Non-standard digits can be used. This can also allow bases greater
than 36.
"""
if base < 2: raise ValueError("Minimum base is 2")
if base > len(digits): raise ValueError("Not enough digits for base")
# Deal with negative numbers
negative = val < 0
val = abs(val)
if complement:
sign = ""
max = base**min_digits
if (val > max) or (not negative and val == max):
raise ValueError("Value out of range for complemented format")
if negative:
val = (max - val)
else:
sign = "-" * negative
# Calculate digits
val_digits = []
while val:
val, digit = divmod(val, base)
val_digits.append(digits[digit])
result = "".join(reversed(val_digits))
leading_digits = (digits[0] * (min_digits - len(result)))
return sign + leading_digits + result
if __name__ == "__main__":
# Quick sanity check
for base in range(2, 37):
for val in range(-1000, 1000):
assert val == int(num_in_base(val, base), base)
# Quick sanity check of complemented format
def comp(val, base, digits):
return num_in_base(val, base, digits, complement = True)
for base in range(2, 37):
for digits in range(1, 11):
limit = base ** digits
for val in range(-min(limit, 1000), 0):
assert limit + val == int(comp(val, base, digits), base)
for val in range(0, min(limit, 1000)):
assert val == int(comp(val, base, digits), base)
