Apply dictionary to pandas dataframe column

Question

I have created the following pandas dataframe:

import pandas as pd 
ds = {'col1':[1,2,2,2,5,1,2,5,6,7]}

df = pd.DataFrame(data=ds)

The dataframe look like this:

print(df)

   col1
0     1
1     2
2     2
3     2
4     5
5     1
6     2
7     5
8     6
9     7

I have then created the following dictionary:

dict = {
    
    1 : 'A',
    2 : 'B',
    3 : 'C',
    4 : 'D',
    5 : 'E',
    6 : 'F',
    7 : 'G',
    8 : 'H',
    9 : 'I',
    10 : 'J'
    }

I need to create a new column (called col2) which results from applying the data dictionary to col1.

I have tried this code:

df['col2'] = dict[df['col1']]
print(df)

But I get this error:

df['col2'] = dict[df['col1']]

TypeError: unhashable type: 'Series'

A solution could be to iterate through each and every row, but that would be very inefficient. Is there a pythonic way to apply the dictionary so to get the following dataframe?

   col1 col2
0     1    A
1     2    B
2     2    B
3     2    B
4     5    E
5     1    A
6     2    B
7     5    E
8     6    F
9     7    G