How to solve - ValueError: could not convert string to float: ''

Question

training_age_in = [1, 2, 3]

training_salary_dep = [5, 9, 10]

m = [(training_age_in[0], training_salary_dep[0]), (training_age_in[1], training_salary_dep[1]),
     (training_age_in[2], training_salary_dep[2])]

intercept_value = open("intercept_value", "r+")

slope_value = open("slope_value", "r+")

input_place = open("input_place", "r+")

intercept = float(intercept_value.read())

slope = float(slope_value.read())

input_place.seek(1)

input_place.write(str(training_age_in[0]))

number0 = float(input_place.read())

predicted_Y0 = intercept + (slope * number0)

error0 = (training_salary_dep[0] - predicted_Y0) ** 2
print(number0)

That's my code and it keeps coming up with a ValueError: could not convert string to float: ''. How could I solve this.