df = pd.DataFrame({'a': np.random.randn(6), 'b': np.random.choice([5, 7, np
    .nan], 6), 'c': np.random.choice(['panda', 'python', 'shark'], 6), 'd':
    np.repeat(list(range(3)), 2), 'e': np.tile(list(range(2)), 3), 'f': pd.date_range(
    '1/1/2011', periods=6, freq='D'), 'g': np.random.choice(pd.date_range(
    '1/1/2011', periods=365, freq='D'), 6, replace=False)})
How to make good reproducible pandas examples