Get list from pandas DataFrame column headers
I want to get a list of the column headers from a pandas DataFrame. The DataFrame will come from user input so I won't know how many columns there will be or what they will be called.
For example, if I'm given a DataFrame like this:
>>> my_dataframe
y gdp cap
0 1 2 5
1 2 3 9
2 8 7 2
3 3 4 7
4 6 7 7
5 4 8 3
6 8 2 8
7 9 9 10
8 6 6 4
9 10 10 7
I would want to get a list like this:
>>> header_list
[y, gdp, cap]
You can get the values as a list by doing:
list(my_dataframe.columns.values)
Also you can simply use:
list(my_dataframe)
There is a built in method which is the most performant:
my_dataframe.columns.values.tolist()
.columns returns an Index , .columns.values returns an array and this has a helper function to return a list .
EDIT
For those who hate typing this is probably the shortest method:
list(df)
Did some quick tests, and perhaps unsurprisingly the built-in version using dataframe.columns.values.tolist() is the fastest:
In [1]: %timeit [column for column in df]
1000 loops, best of 3: 81.6 µs per loop
In [2]: %timeit df.columns.values.tolist()
10000 loops, best of 3: 16.1 µs per loop
In [3]: %timeit list(df)
10000 loops, best of 3: 44.9 µs per loop
In [4]: % timeit list(df.columns.values)
10000 loops, best of 3: 38.4 µs per loop
(I still really like the list(dataframe) though, so thanks EdChum!)
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