circuitpython/tests/float/string_format_modulo2.py at stable · cionicwear/circuitpython

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# test formatting floats with large precision, that it doesn't overflow the buffer

def test(num, num_str):

if num == float('inf') or num == 0.0 and num_str != '0.0':

# skip numbers that overflow or underflow the FP precision

return

for kind in ('e', 'f', 'g'):

# check precision either side of the size of the buffer (32 bytes)

for prec in range(23, 36, 2):

fmt = '%.' + '%d' % prec + kind

s = fmt % num

check = abs(float(s) - num)

if num > 1:

check /= num

if check > 1e-6:

print('FAIL', num_str, fmt, s, len(s), check)

# check pure zero

test(0.0, '0.0')

# check some powers of 10, making sure to include exponents with 3 digits

for e in range(-8, 8):

num = pow(10, e)

test(num, '1e%d' % e)