如何使用 .loc[] 访问数据框的最后一列？

Question

is it possible to get access of last column of a data frame and last row of a data frame by using

.loc[]

I saw this link

https://stackoverflow.com/questions/40144769/how-to-select-the-last-column-of-dataframe

but in this discussion no one spoke about loc . I would be appreciate if someone helps me to to solve this problem. thanks a lot.

Answer 1

` df_test = pd.DataFrame([2012, 2015, 2010], columns=['start_date'])

df_test['end_date'] = [2014, 2017, 2020]

last_index = list(df_test.index)[-1]

last_col = list(df_test.columns)[-1]

df_test.loc[last_index, last_col] `

enter image description here

Answer 2

我认为这会起作用：df.iloc[-1:,-1:]

Answer 3

That is what iloc is made for

The loc method locates data by label. The iloc method locates data by integer index. If no column names are defined, this would be the easiest way:

data = [[1, 1, 1, 1, 1], [2, 2, 2, 2, 2], [3, 3, 3, 3, 3]]
df = pd.DataFrame(data)
df.iloc[-1,:]

output:
0    3
1    3
2    3
3    3
4    3

Last row would be accordingly:

df.iloc[:,-1]

output:
0    1
1    2
2    3

If you still want to use loc , the last column you wish to refer to needs a name since location by interger indexing is not possible.

df = pd.DataFrame({'first_column': [50, 60], 'last_column': [100, 120]})

df.loc[:]['last_column']

output:
0    100
1    120