Pandas Dataframe subset not working as expected

This seemingly simple exercise is throwing me off my tracks, I'm sure it's something simple skipping my eye.

Let's say I have a dataframe

 datas = pd.DataFrame({'age':[10,20,30],
                          'name':['John','Mark','Lisa']})

I now want to subset the dataframe by the name 'Mark' so I did:

    if (datas['name']=='Mark').any():
        datas.loc[datas['name'] == 'Mark']
    else:
        print('no')

Expected result is

age name
20  Mark

but I get the original dataframe back again, please assist.

I've looked at several posts but none seems to help.

Posts example I looked at: Check if string is in a pandas dataframe