I'm using DataFrame and couldn't find a site that explains the title, so I'll share it. How to specify the default Index label.
First, prepare a suitable DataFrame.
import pandas as pd import numpy as np df = pd.DataFrame(np.arange(12).reshape(3, 4), columns=['col_0', 'col_1', 'col_2', 'col_3'], index=['row_0', 'row_1', 'row_2'])
↓ Such a DataFrame is created.
To get the value of the
col_2 column of the
row_1 row from this DataFrame, do as follows.
df.at["row_1", "col_2"] # => 6
So far, the basic usage of the at method.
But what if the Index label isn't specified?
import pandas as pd import numpy as np df = pd.DataFrame(np.arange(12).reshape(3, 4), columns=['col_0', 'col_1', 'col_2', 'col_3'])
↓ This is the DataFrame. There is no Index label. (Index names are 0, 1, 2 by default)
What should I do if I want to get the values of the
1th row and
col_2th column of this DataFrame?
Actually, I was able to get it with the following writing style.
df.at[1, "col_2"] # => 6
** It seems that
1 does not need
df.at["1", "col_2"] # =>error!
Please note that this will result in an error. Until now, I thought that I had to specify the index with the iat method and iloc method, but you can also specify the label with the default index!
This time, I shared the method of specifying the default Index label with the at method. Thank you for reading to the end. If you have any questions, please feel free to comment.