How to slice a Pandas Data Frame by position?

Question

I have a Pandas Data Frame object that has 1000 rows and 10 columns. I would simply like to slice the Data Frame and take the first 10 rows. How can I do this? I've been trying to use this:

>>> df.shape
(1000,10)
>>> my_slice = df.ix[10,:]
>>> my_slice.shape
(10,)

Shouldn't my_slice be the first ten rows, ie. a 10 x 10 Data Frame? How can I get the first ten rows, such that my_slice is a 10x10 Data Frame object? Thanks.

Answer 1

http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.head.html?highlight=head#pandas.DataFrame.head

df2 = df.head(10)

should do the trick

Answer 2

您还可以为方便起见：

df[:10]

Answer 3

df.ix[10,:] gives you all the columns from the 10th row. In your case you want everything up to the 10th row which is df.ix[:9,:] . Note that the right end of the slice range is inclusive: http://pandas.sourceforge.net/gotchas.html#endpoints-are-inclusive

Answer 4

I can see at least three options:

Option 1

df[:10]

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Option 2

Using head

df.head(10)

For negative values of n, this function returns all rows except the last n rows, equivalent to df[:-n] [Source] .

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Option 3

Using iloc

df.iloc[:10]

Answer 5

DataFrame[:n]将返回前 n 行。