return thing

def formatfloat(thing):
    return '%.3g' % float(thing)
x = {'a': [1.05600000001, 2.34581736481, [8.1111111112, 9.999990111111]],
    'b': [3.05600000001, 4.34581736481, [5.1111111112, 6.999990111111]]}
print(pformat(x, formatfloat))
Rounding decimals in nested data structures in Python