Python以什么顺序读取代码？ （包括样本代码）

Question

我目前正在学习如何使用Python进行编码，而且我在我正在学习的书中偶然发现了这些代码（学习Python的方法很难[我不建议任何人开始编写顺便说一句btw]）。

from sys import exit
def gold_room():
    print "This room is full of gold. How much do you take?"

    next = raw_input("> ")
    if "0" in next or "1" in next:
        how_much = int(next)
    else:
        dead("Man, learn to type a number.")

    if how_much < 50:
        print "Nice, you're not greedy, you win!"
        exit(0)
    else:
        dead("You greedy bastard!")

def bear_room():
    print "There is a bear here."
    print "The bear has a bunch of honey."
    print "The fat bear is in front of another door."
    print "How are you going to move the bear?"
    bear_moved = False

    while True:
        next = raw_input("> ")

        if next == "Take honey":
            dead("The bear looks at you then slaps you.")
        elif next == "taunt bear" and not bear_moved:
            print "The bear has moved from the door. You can go through it now."
            bear_moved = True
        elif next == "Taunt Bear" and bear_moved:
            dead("The bear gets pissed off and chews your legs off.")
        elif next == "open door" and bear_moved:
            gold_room()
        else:
            print "I got no idea what that means."

def cthulhu_room():
    print "Here you see the great evil Cthulhu."
    print "He, it, whatever stares at you and you go insane."
    print "Do you flee for your life or eat your head?"

    next = raw_input("> ")

    if "flee" in next:
        start()
    elif "head" in next:
        dead("Well that was tasty!")
    else:
        cthulhu_room()

def dead(why):
    print why, "Good job!"
    exit(0)

def start():
    print "You are in a dark room."
    print "There is a door to your right and left."
    print "Which one do you take?"

    next = raw_input("> ")

    if next == "left":
        bear_room()
    elif next == "right":
        cthulhu_room()
    else:
        dead("You stumble around the room until you starve.")

start()

我一直认为Python从左到右，从上到下读代码，但在上面的代码中，它开始运行程序     def start（）：         打印“你在一个黑暗的房间里。” 我不明白是什么让Python做到这一点，如果有人能为我清除它将会有很大的帮助。非常感谢。

Answer 1

  

我一直认为Python从左到右，从上到下读取代码

读取，是，自上而下，从左到右。

仅def gold_room(): 定义功能gold_room，它不会运行。如果没有gold_room()，则永远不会执行。与start()相同。