micropython/tests/unix/ffi_float.py

# test ffi float support
try:
    import ffi
except ImportError:
    print("SKIP")
    raise SystemExit


def ffi_open(names):
    err = None
    for n in names:
        try:
            mod = ffi.open(n)
            return mod
        except OSError as e:
            err = e
    raise err

libc = ffi_open(('libc.so', 'libc.so.0', 'libc.so.6', 'libc.dylib'))

strtof = libc.func("f", "strtof", "sp")
print('%.6f' % strtof('1.23', None))

strtod = libc.func("d", "strtod", "sp")
print('%.6f' % strtod('1.23', None))

# test passing double and float args
libm = ffi_open(('libm.so', 'libm.so.6', 'libc.so.0', 'libc.so.6', 'libc.dylib'))
tgamma = libm.func('d', 'tgamma', 'd')
for fun in (tgamma,):
    for val in (0.5, 1, 1.0, 1.5, 4, 4.0):
        print('%.6f' % fun(val))