to-numpy-list.md

Using to_numpy with tolist

• to_numpy
• tolist

import pandas as pd

df = pd.DataFrame({"A": [1, 2], "B": [3, 4]})

print(df)

"""
Dataframe becomes

  A  B
0  1  3
1  2  4
"""

new_df = df.to_numpy()

print(new_df)

"""
Dataframe becomes a NumPy array after using to_numpy on it

[[1 3]
 [2 4]]
 """

print(new_df.tolist())
"""
Now we convert that NumPy array to a python list

[[1, 3], [2, 4]]
"""

Note:

By default, the dtype of the returned array will be the common NumPy dtype of all types in the DataFrame. For example, if the dtypes are float16 and float32, the results dtype will be float32. This may require copying data and coercing values, which may be expensive.