import decimal
import random

def random_float(start, end):
    return random.random()*(end-start)+start

def random_decimal(start, end, decimal_places=2):
    d = str(random_float(start, end))
    print d
    print decimal.getcontext()
    return decimal.Decimal(d).quantize(decimal.Decimal(10 ** (-decimal_places)))

print random_decimal(1000, 10000)

2430.39449204
Context(prec=28, rounding=ROUND_HALF_EVEN, Emin=-999999999, Emax=999999999, capitals=1, flags=[], traps=[Overflow, DivisionByZero, InvalidOperation])
Traceback (most recent call last):
  File "decimal_test.py", line 15, in <module>
    print random_decimal(1000, 10000)
  File "decimal_test.py", line 12, in random_decimal
    return decimal.Decimal(d).quantize(decimal.Decimal(10 ** -2))
  File "/usr/lib/python2.7/decimal.py", line 2464, in quantize
    'quantize result has too many digits for current context')
  File "/usr/lib/python2.7/decimal.py", line 3866, in _raise_error
    raise error(explanation)
decimal.InvalidOperation: quantize result has too many digits for current context

#Вместо
decimal.Decimal(10 ** (-decimal_places))
#Надо
decimal.Decimal(10)**(-decimal_places)