尝试求和，但似乎行不通

Question

我正在学习python，正在研究这个问题，但似乎不能让它工作。当执行这段代码时，我在单独的行上得到数字1到8。我怎么才能打印出8的数字呢？

honor_roll_count = 0
student_grades = ["A", "C", "B", "B", "C", "A", "F", "B", "B", "B", "C", "A"]
for grade in student_grades:
    if grade in "AB":
        honor_roll_count = honor_roll_count + 1
        print honor_roll_count

Answer 1

您的print是缩进的，这意味着它在for循环内的if中，所以每个"A“或"B”都会发生这种情况。在循环之后，你想要它。

for grade in student_grades:
    if grade in "AB":
        honor_roll_count = honor_roll_count + 1
print honor_roll_count

Answer 2

将print语句向左移动，有两个缩进级别：

for grade in student_grades:
    if grade in "AB":
        honor_roll_count = honor_roll_count + 1
print honor_roll_count

现在它将在循环完成后执行，而不是在循环的每次迭代中执行。

Answer 3

honor_roll_count = 0
student_grades = ["A", "C", "B", "B", "C", "A", "F", "B", "B", "B", "C", "A"]
for grade in student_grades:
    if grade in "AB":
        honor_roll_count += 1
print honor_roll_count