python - 我被困在“未定义”但它看起来对我来说已定义

Question

我被困住了。我不知道我哪里出错了。

def convert_distance(miles):
    km = miles * 1.6  # approximately 1.6 km in 1 mile

my_trip_miles = 55

my_trip_km = km * my_trip_miles

print("The distance in kilometers is " + str(my_trip_km))

round_trip= my_trip_km * 2

print("The round-trip in kilometers is " + str(round_trip))

我不断得到“公里”没有定义。

标签： pythonconverters

Answer 1

你应该从你的函数返回值

def convert_distance(miles):
    km = miles * 1.6  # approximately 1.6 km in 1 mile
    return km

然后将其分配给一个变量

my_trip_km = convert_distance(my_trip_miles)