The .loc attribute of a DataFrame is used to select values using the labels of the entries. It can be used to retrieve single scalar values from a DataFrame (using singular string labels for both row and column), or multiple values from a DataFrame (using lists of row/column labels). Single and multiple indexing can also be used in combination to get multiple values from a single row or column. The following lines of code illustrate the retrieval of a single scalar value from the df DataFrame:
value = df3.loc[0,'new_col5']
print(value)
The output will be 7.0.
Single/multiple values can also be set using the .loc attribute and an equals sign:
df3.loc[[2,3,4],['new_col4','new_col5']] = 1
print(df3)
The output is as follows:
col3 new_col1 new_col2 new_col3 new_col4 new_col5 new_col6 0 x 0 5 5 7.0 10 1 y 0 7 7 8.0 11 2 z 0 9 1 1.0 12 3 a 0 11 1 1.0 13 4 b 0 13 1 1.0 14 5 c 0 15 21 9.5 15 6 d 0 17 23 10.5 16