def celsius_to_kelvin(value_celsius):
    value_kelvin = 0.0

    value_kelvin = value_celsius + 273.15
    return value_kelvin

def kelvin_to_celsius(value_kelvin):
    value_c = 10.0
    
    value_c = value_kelvin -273.15
    return value_c

value_c = 10.0
print(value_c, 'C is', celsius_to_kelvin(value_c), 'K')

value_k = float(input())
print(value_k, 'K is', kelvin_to_celsius(value_k), 'C')

def kelvin_to_celsius(value_kelvin):
    value_celsius = 0.0
    
    value_celsius = value_kelvin - 273.15
    return value_celsius

试试这个：

def celsius_to_kelvin(value_celsius):
    value_kelvin = 0.0

    value_kelvin = value_celsius + 273.15
    return value_kelvin

def kelvin_to_celsius(value_kelvin):
    value_c = 0.0
    
    value_c = value_kelvin -273.15
    return value_c
    
    

value_c = 10.0
print(value_c, 'C is', celsius_to_kelvin(value_c), 'K')

value_k = float(input())
print(value_k, 'K is', kelvin_to_celsius(value_k), 'C')

def celsius_to_kelvin(value_celsius):
    value_kelvin = 0.0

    value_kelvin = value_celsius + 273.15
    return value_kelvin

def kelvin_to_celsius(value_kelvin):
    value_celsius = 0.0

    value_celsius = value_kelvin - 273.15
    return value_celsius

value_k = 10.0

value_c = 10.0
print(value_c, 'C is', celsius_to_kelvin(value_c), 'K')

value_k = float(input())
print(value_k, 'K is', kelvin_to_celsius(value_k), 'C')

基本上你只是复制了上面的代码。2你只是重新排列了代码中的一些变量，并将加法改为减法。3（正确地缩进def）

def kelvin_to_celsius(value_kelvin):
    value_celsius = 0.0

    value_celsius = value_kelvin - 273.15
    return value_celsius