使用长度小于pandas数据框的numpy数组填充pandas数据框

Question

df = pd.DataFrame(index=pd.date_range('2017-01-01', '2017-01-10', freq='D'), columns=['test'])

vals = np.array([1.0, 2.0])

df['test'] = vals

I get this error: ValueError: Length of values does not match length of index

Any way I can fix it? This error is arising because lenght of vals is less than length of df . I want to insert numpy NaNs for the places where I have no values.

Answer 1

您可以像这样仅分配第一行：

df['test'][:len(vals)] = vals