在我的代码中,项目percentgrade不会在for循环的每次迭代中附加到列表lnpercentgrade,但我不确定原因。当我尝试在lnpercentgrade中汇总项目时(在代码的末尾),我返回0因为lnpercentgrade是empy。 我将lnpercentgrades声明为maininput()函数之外的全局变量,因为当我尝试求和(lnpercentgrades)时,在代码的底部,我返回“lnpercentgrades not defined”。
我猜想在maininput()函数内部没有以某种方式修改lnpercentgrades,即使我确信我在.append函数之前正确输入了它。
我真正要做的是将总和(lnpercentgrades)与100相匹配,但是当我输入5项全部值为20时,总和为0而不是100。
重要的行标有箭头<<<<<<<<<<<<<<<<<<<<<<< <
lnpercentgrades = [] <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
def maininput():
numtests = int(input("Enter # of tests:"))
numassign = int(input("Enter # of assignments:"))
numquizzes = int(input("Enter # of quizzes:"))
numlabs = int(input("Enter # of labs:"))
l = [numtests, numassign, numquizzes, numlabs]
ln = ["test", "assignments", "quizzes", "labs"]
lnpercentgrades = [] <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
testwavg = None
numassignwavg = None
numquizzeswavg = None
numlabswavg = None
numfinalwavg = None
lnwavg = [testwavg, numassignwavg, numquizzeswavg, numlabswavg]
print(l[0])
print("Is there a separately weighted final?")
yn = int(input("Enter 1 for yes. 2 for no:"))
while (yn > 2 or yn < 1):
yn = int(input("Enter 1 for yes. 2 for no, please:"))
n = 4
if yn == 1:
final = 1
l.append(final)
ln.append("final")
lnwavg.append(numfinalwavg)
n = 5
for i in range (n):
if l[i] > 0:
print("Enter % of total grade of",ln[i],":")
percentgrade = float(input(""))
print("you inputed:", percentgrade)
lnpercentgrades.append(percentgrade) <<<<<<<<<<<<<<<<<<<<<<
percentgrade = percentgrade*.01
varscoreslist = []
for x in range(l[i]):
print("Enter score of", ln[i], x+1,"as a fraction:")
from fractions import Fraction
inputfrac = input("")
varscore = float(sum(Fraction(s) for s in inputfrac.split()))
#the above converts fractional inputs to decimals
varscoreslist.append(varscore)
if ln[i] == "labs":
score = sum(varscoreslist)
else:
sumscores = sum(varscoreslist)
score = sumscores/l[i]
lnwavg[i] = score*percentgrade
maininput()
print(lnpercentgrades)
print("sum of percent of grades", sum(lnpercentgrades)) <<<<<<<<<<<<<<<
if float(sum(lnpercentgrades)) != 100: <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
print("Sorry, the grade percent of each item enter did not sum to 100:")
print("Program will rerun.")
input("")
maininput()
coursegrade = sum(lnwavg)
print("Your course grade is:", coursegrade)
input("")
答案 0 :(得分:6)
乍一看,您可能会遇到范围问题。您正在修改函数内部的列表,但请记住,这是列表的本地副本。尽管您在外部范围内声明它,但您没有使用global
作为前缀,这意味着它会创建一个函数本地副本,执行其业务然后退出,而不会影响“主”列表所有
我建议修改你的功能以返回你想要的列表,这样你就可以按照你的期望使用它们。这是一个基本的例子:
def MyFunc():
l1 = ['my', 'first', 'list']
l2 = ['another', 'list']
return l1, l2
main_list, second_list = MyFunc()
print(main_list)
print(second_list)
将输出:
['my', 'first', 'list']
['another', 'list']
如果你真的想要将变量保留在外部作用域中,你必须在函数内部加global
(我可能会使用第一种方法):
main_list = []
second_list = []
def MyFunc():
global main_list
global second_list
main_list = ['more', 'good', 'stuff']
second_list = ['another', 'list']
MyFunc()
print(main_list) # ['more', 'good', 'stuff']
print(second_list) # ['another', 'list']