Python 3.x range-like function with decimal step

frange.py

import decimal

def frange(start, stop, step, include_stop=True):
    """Range-like function that accepts decimal step values."""

    # To avoid rounding issues
    # We cast the floats to string and then to decimals
    # see: docs on Decimal(0.1) != Decimal('0.1')
    dstep = decimal.Decimal(str(step))

    # We round the boundaries to the precision of the step
    # to avoid further issues with limits.
    precision = -1 * dstep.as_tuple().exponent
    val = decimal.Decimal(f"{start:.{precision}f}")
    end = decimal.Decimal(f"{stop:.{precision}f}")

    # Define stopping condition
    if include_stop:
        check = lambda v: v <= end
    else:
        check = lambda v: v < end

    n = 0  # number of cycles
    while check(val):
        yield start + n*step  # return the "full precision" value
        val += dstep  # to keep the boundary condition
        n += 1