Python - 从文件中获取缩进错误

问：

我正在尝试用python制作一个小程序，没有什么复杂的，但非常长。刚才，我修改了“if”语句的一个条件，然后通过 MacOS 终端运行它，因为它有一个 Python shell / IDLE（我不知道它在英文中是如何称呼的）。

我的文档正好有 456 行，我得到的“IndentationError”位于“第 457 行”，这是输出：

文件“/Volumes/my usb key/MAIN_0.3.py”，第 457 行

                    ^

IndentationError：预期为缩进块

我真的不知道该怎么做，因为我的程序的最后一行都是评论。如果你想要一些代码，我会尽量为大家简单地（用英语）表达，但我想先知道在“终端”中运行它是否没有问题，因为它真的很奇怪。

编辑：这是一些代码：

#coding= utf-8
#here I put a lot of variables(38), which are all 'int' or 'randint(x, y)'
#then I define some functions, which are all calculus
#here is the main loop :
while (a!=10) and (b > 10):
    function_a(a)
    c=0
    while (c != 1) and (b > 0):
        while b != 0:
            print "\n"
            d=randint(0,20)
            if 0 <= d <= 3: #commentary explaining my program for my buddies at school
                b=function_b(b, e, f, g, h, i, j, a, k, l)
                if b <= 0: #commentary
                    m += n
                    p += a_b
                    if p > 1000: #commentary
                        p -= 1000
                        k += 1
                        print " BRAVO !"
                        print " now", k
                        time.sleep(1)
                        b += b_levelup
                        e += e_levelup
                        f += f_levelup
                        print " you won", b_levelup, "points"
                        time.sleep(1)
                        print " you won", e_levelup, "points"
                        time.sleep(1)
                        print " you won", f_levelup, "points"
                        time.sleep(1)
                print "\n"*2

            if 3 < d <= 8: #commentary

                b=function_b(b, e, f, g, q, r, s, a, k, t)

                if b <= 0: #commentary
                    m += u
                    p += v

                    if p > 1000: #
                        p -= 1000
                        k += 1
                        print " BRAVO !"
                        print " now", k
                        time.sleep(1)
                        b += b_levelup
                        e += e_levelup
                        f += f_levelup
                        print " you won", b_levelup, "points"
                        time.sleep(1)
                        print " you won", e_levelup, "points"
                        time.sleep(1)
                        print " you won", f_levelup, "points"
                        time.sleep(1)
                print "\n"*2

            if 8 < d <= 14: #commentary

                b=function_b(b, e, f, g, w, x, y, a, z, k, a_a)

                if b <= 0: #commentary
                    m += n
                    p += a_b
                    if p > 1000: #commentary
                        p -= 1000
                        k += 1
                        print " BRAVO !"
                        print " now", k
                        time.sleep(1)
                        b += b_levelup
                        e += e_levelup
                        f += f_levelup
                        print " you won", b_levelup, "points"
                        time.sleep(1)
                        print " you won", e_levelup, "points"
                        time.sleep(1)
                        print " you won", f_levelup, "points"
                        time.sleep(1)
                print "\n"*2

            if 15 <= d <= 16:#commentary
                a_c += 1
                function_c()

            if d == 17: #commentary
                a_d += 1
                function_d()

            #boss commentary
            if (d == 18) and (a_d == 0):
                print " mkay"
                time.sleep(2)
                print " nope"
                print " next door"

            #commentary
            if (d == 18) and (a_d >= 1):
                print " arrived"
                time.sleep(2)
                print " wanna go ?"
                print " yes - 1"
                print " No - any other"
                a_e=input(" ")
                if a_e == 1:
                    #boss commentary