mars.dataframe.DataFrame.head#
- DataFrame.head(n=5)#
Return the first n rows.
This function returns the first n rows for the object based on position. It is useful for quickly testing if your object has the right type of data in it.
For negative values of n, this function returns all rows except the last n rows, equivalent to
df[:-n]
.- Parameters
n (int, default 5) – Number of rows to select.
- Returns
The first n rows of the caller object.
- Return type
same type as caller
See also
DataFrame.tail
Returns the last n rows.
Examples
>>> import mars.dataframe as md >>> df = md.DataFrame({'animal': ['alligator', 'bee', 'falcon', 'lion', ... 'monkey', 'parrot', 'shark', 'whale', 'zebra']}) >>> df.execute() animal 0 alligator 1 bee 2 falcon 3 lion 4 monkey 5 parrot 6 shark 7 whale 8 zebra
Viewing the first 5 lines
>>> df.head().execute() animal 0 alligator 1 bee 2 falcon 3 lion 4 monkey
Viewing the first n lines (three in this case)
>>> df.head(3).execute() animal 0 alligator 1 bee 2 falcon
For negative values of n
>>> df.head(-3).execute() animal 0 alligator 1 bee 2 falcon 3 lion 4 monkey 5 parrot