import pandas as pd

content = ['T', 'F'] * 10

data = pd.DataFrame(content, columns=['Y'])
print(data)
Y
0 T
1 F
2 T
3 F
4 T
5 F
6 T
7 F
8 T
9 F
10 T
11 F
12 T
13 F
14 T
15 F
16 T
17 F
18 T
19 F

data.loc[data['Y'] == 'T'] = 1
data.loc[data['Y'] == 'F'] = 0

print(data)
 Y
0 1
1 0
2 1
3 0
4 1
5 0
6 1
7 0
8 1
9 0
10 1
11 0
12 1
13 0
14 1
15 0
16 1
17 0
18 1
19 0