T1 = ['13', '17', '18', '21', '32'] #list with numbers stored as string

T3 = list(map(int, T1))
print(T3) #prints [13, 17, 18, 21, 32]

#or
T4 = [int(x) for x in T1]
print(T4) #prints [13, 17, 18, 21, 32]