Following code using default credit card dataset:
df = h2o.import_file("CreditCard_Cat-train.csv")
dropped = ["PAY_0"]
has following output:
which shows that the variable `dropped` has change after the `df.drop` call from `['PAY_0']` to `[-7]`.
This means that user can not call `drop` on multiple frames in a row with the same input variable.