使用變量，裏面一個

Question

我的工作中，我需要使用在定義函數中定義的變量，定義環外的任務定義時，代碼：

def startmenu(): #this is to call back here at any time 
    startmenuoption = 1 
    while startmenuoption == 1: 
     startoption = input("Would you like to create, check or quit?") 
     if startoption in ["Check", "check"]: 
      print("You chose check!") 
      startmenuoption = 0 
     elif startoption in ["Create", "create"]: 
      print("You chose create!") 
      startmenuoption = 0 
     elif startoption in ["Quit", "quit"]: 
      print("You quit!") 
      startmenuoption = 0 
     else: 
      print("Invalid reason try again!") 

startmenu() 
if startoption in ["Check"]: 
    print("Checking!") 
else: 
    print("Okay!") 

我知道它似乎是一個簡單的選項來刪除定義循環，但這正是我想要避免的，因爲它是我所需要的。

Answer 1

將if..else部分移至方法。

def startmenu():#this is to call back here at any time 
    startmenuoption = 1 
    while startmenuoption == 1: 
     startoption = raw_input("Would you like to create, check or quit?") 
     if startoption in ["Check","check"]: 
      print("You chose check!") 
      startmenuoption = 0 
     elif startoption in ["Create","create"]: 
      print("You chose create!") 
      startmenuoption = 0 
     elif startoption in ["Quit","quit"]: 
      print("You quit!") 
      startmenuoption = 0 
     else: 
      print("Invalid reason try again!") 

    if startoption in ["Check"]: 
     print("Checking!") 
    else: 
     print("Okay!") 
startmenu() 

Answer 2

對於訪問內部函數中的變量，你可以做這樣的：

def fun(): 
    fun.x=1 

fun() 
print(fun.x)     #will print 1 

或者只是使用global variable，您可以訪問和使用global在你的函數修改。

x=None 

def fun(): 
    global x 
    x=1 

fun() 
print(x)      #will print 1 

注：我會建議使用global，而不是第一個方法。

Answer 3

有幾個解決方案。你可以通過這個作爲參數傳入你的函數，你調用STARTMENU（之前定義它）是這樣的：

startoption =無 STARTMENU（startoption）

你也可以返回值

ANS = STARTMENU（） 在STARTMENU回報startoption

Answer 4

我的解決辦法是，當你調用函數像這樣返回值：

def startmenu(): #this is to call back here at any time 
    startmenuoption = 1 
    while startmenuoption == 1: 
     startoption = input("Would you like to create, check or quit?") 
     if startoption in ["Check", "check"]: 
      print("You chose check!") 
      startmenuoption = 0 
     elif startoption in ["Create", "create"]: 
      print("You chose create!") 
      startmenuoption = 0 
     elif startoption in ["Quit", "quit"]: 
      print("You quit!") 
      startmenuoption = 0 
     else: 
      print("Invalid reason try again!") 
    return startoption 

startoption = startmenu() 
if startoption in ["Check"]: 
    print("Checking!") 
else: 
    print("Okay!")