def ds_format(ds, input_format, output_format):
    return datetime.strptime(ds, input_format).strftime(output_format)
Test significant digits patterns
dataset/ETHPy150Open airbnb/airflow/airflow/macros/__init__.py/ds_format--crossover with--dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/Babel-0.9.6/babel/tests/numbers.py/FormatDecimalTestCase.test_significant_digits