I recently came across one such scenario. The following are some of the ways to check if a dataframe is empty.
df.count() == 0
If a dataframe carries a full record, you should avoid using count(), as it is inefficient. However there might be some situations where you are very certain that the dataframe would have either a single row or no record at all, in that case you should go for count().
For an ideal case I would suggest you to check the head element if it is empty or not.
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