Python 为什么这个程序总是返回“0”;无”;最后呢? def ticketdo(tickethave): 短语=“您的总金额为美元” 如果tickethave==“n”: 打印短语+“22” 伊里夫·蒂克瑟夫!=“n”: tickethour=输入(“您的车停了多长时间?”) 如果tickethour
是因为Python 为什么这个程序总是返回“0”;无”;最后呢? def ticketdo(tickethave): 短语=“您的总金额为美元” 如果tickethave==“n”: 打印短语+“22” 伊里夫·蒂克瑟夫!=“n”: tickethour=输入(“您的车停了多长时间?”) 如果tickethour,python,if-statement,Python,If Statement,是因为ticketdo没有返回任何内容。默认情况下,不返回任何内容的函数返回None。这是因为,在Python中,所有函数都必须返回某些内容 此外,通过这样做: def ticketdo(tickethave): phrase = "Your total is $" if tickethave == "n": print phrase + "22" elif tickethave != "n": tickethour = input("Ho
ticketdo
没有返回任何内容。默认情况下,不返回任何内容的函数返回None
。这是因为,在Python中,所有函数都必须返回某些内容
此外,通过这样做:
def ticketdo(tickethave):
phrase = "Your total is $"
if tickethave == "n":
print phrase + "22"
elif tickethave != "n":
tickethour = input("How long has your car been parked?")
if tickethour <=1:
print phrase + "2"
elif tickethour <=2:
print phrase + "4"
elif tickethour <=3:
print phrase + "6"
elif tickethour <=4:
print phrase + "8"
elif tickethour <=5:
print phrase + "10"
elif tickethour <=6:
print phrase + "12"
elif tickethour <=7:
print phrase + "14"
elif tickethour <=8:
print phrase + "16"
elif tickethour > 8:
print phrase + "20"
def main():
tickethave = raw_input("Do you have your ticket? (y/n): ")
print ticketdo(tickethave)
main()
您正在告诉Python打印ticketdo
的返回值
因此,要解决此问题,请将
print
放在该行,或者让ticketdo
返回某个内容,然后打印该内容(根据您的代码结构判断,您可能需要第一个解决方案)。您正在打印ticketdo
函数的返回值。由于您没有明确指定该函数的返回值,它将自动返回默认值,即None
,这正是您要打印到stdout的内容
如果只想调用函数而不打印其返回值,只需执行以下操作:
print ticketdo(tickethave)
调用函数时,不需要对函数的返回值进行任何处理。使用返回值是完全可选的。我只是在
ticketdo(tickethave)
之前删除打印:
#/usr/bin/env python
def ticketdo(tickethave):
短语=“您的总金额为美元”
如果tickethave==“n”:
打印短语+“22”
伊里夫·蒂克瑟夫!=“n”:
tickethour=输入(“您的车停了多长时间?”)
如果您选择了tickethour,请使用代码块使此代码更形象。
ticketdo(tickethave)
#!/usr/bin/env python
def ticketdo(tickethave):
phrase = "Your total is $"
if tickethave == "n":
print phrase + "22"
elif tickethave != "n":
tickethour = input("How long has your car been parked?")
if tickethour <=1:
print phrase + "2"
elif tickethour <=2:
print phrase + "4"
elif tickethour <=3:
print phrase + "6"
elif tickethour <=4:
print phrase + "8"
elif tickethour <=5:
print phrase + "10"
elif tickethour <=6:
print phrase + "12"
elif tickethour <=7:
print phrase + "14"
elif tickethour <=8:
print phrase + "16"
elif tickethour > 8:
print phrase + "20"
def main():
tickethave = raw_input("Do you have your ticket? (y/n): ")
ticketdo(tickethave)
if __name__ == "__main__":
main()