How to extract an item from a list and add it as a column in dataframe?

I have 3 lists like as shown below

numeric_cols = df.select_dtypes(include=np.number).columns # 3 items `qty`, `age`, `sqft`
date_cols = df.select_dtypes(include=['datetime64']).columns # 2 items
string_cols = df.select_dtypes(include=['object']).columns # 3 items `bucket`, `category`, `level`

Now, I would like to

a) select only one item from numeric cols – qty and all the items from string_cols (so dataframe has to have only 4 columns)

I tried the below

df[[*string_cols]] = df[[*string_cols]]
df.insert(2, "Qty",df['Qty'],True)

Please note that what I have shown is just a sample. In real data, I have millions of rows and 100’s of columns. Hence, I would like to follow the above approach.

Can guide me on how can I do this efficiently?

>Solution :

You can select subset of columns using a list of column names:

new_df = df[[*string_cols] + ['Qty']]