Practicle Exam 3, Question no 2

In question no 2, where we have to fill in the blank to get the result for minimum value across the data set. As per your result answer is (minimum, axis=0)
the complete syntax will be
np.minimum(text_df, axis=0)
when i try to implement the above statement, i get an error stating

---------------------------------------------------------------------------

ValueError                                Traceback (most recent call last)

<ipython-input-20-2363781753c0> in <module>()
----> 1 np.minimum(df, axis=0)

ValueError: invalid number of arguments

here i gave my dataset name df.
will you please elaborate on this, why this is happening