擅长:python、mysql、java
<p>根据定义,在全局范围定义的任何名称都是全局的</p>
<p><code>global</code>语句用于<em>另一个</em>范围中,以将一个名称标记为全局名称,否则该名称将是本地的</p>
<pre><code>import os.path
from os import path
shoppinglist = []
def main():
Displaylist()
RunItemAction()
def Displaylist():
global useraction
i = 0
if (len(shoppinglist)>0):
while (i<=len(shoppinglist)):
print(shoppinglist[i] +"\n")
i+=1
useraction = str(input("Do you want to add, remove, or search for an item? "))
useraction = useraction.upper()
def RunItemAction():
global useraction
if( useraction == "ADD"):
AddItem()
</code></pre>
<p>也就是说,根本不要使用全局变量。将参数传递给函数,并使其返回值</p>