在使用 Python 编程时，代码执行失败可能由多种原因引起。常见的问题包括语法错误、逻辑错误、环境配置问题、依赖项缺失等。下面列举了一些常见的 Python 代码执行失败的原因及对应的解决方案。
1、问题背景
在尝试运行一个 Python 代码时，代码没有执行，也没有产生任何错误提示。代码如下：
代码语言：javascript复制from sys import exit
from random import randint
class Scene(object):
def enter(self):
print "This is not yet configured. Subclass it and implement enter"
exit(1)
class Engine(object):
def __init__(self, scene_map):
self.scene_map = scene_map
def play(self):
current_scene = self.scene_map.opening_scene()
while True:
print "n-------------"
next_scene_name = current_scene.enter()
current_scene = self.scene_map.next_scene(next_scene_name)
class Death(Scene):
quips = [
'Shame on you. You lost!',
'You are such a loser',
'Even my dog is better at this'
]
def enter(self):
print Death.quips[randint(0, (len(self.quips) - 1))]
exit(1)
class CentralCorridor(Scene):
def enter(self):
print "The Gothoms of Planet Parcel # 25 have invade your ship and "
print "killed all your crew members. You are the last one to survive."
print "Your last mission is to get the neutron destruction bomb from "
print "the Laser Weapons Armory and use it to destroy the bridge and get"
print "to the escape pod from where you can escape after putting in the"
print "correct pod."
print "n"
print "Meanwhile you are in the central corridor where a Gothom stands"
print "in front of you. You need to kill him if you want to proceed to"
print "the Laser Weapons Armory. What will you do now - 'shoot', 'dodge' or 'tell him a joke'"
action = raw_input(">")
if action == "shoot":
print "You try to shoot him but he reacts faster than your expectations"
print "and kills you"
return 'death'
elif action == "dodge":
print "You thought that you will escape his vision. Poor try lad!"
print "He kills you"
return 'death'
elif action == "tell him a joke":
print "You seem to have told him a pretty funny joke and while he laughs"
print "you stab him and the Gothom is killed. Nice start!"
return 'laser_weapon_armory'
else:
print "DOES NOT COMPUTE!"
return 'central_corridor'
class LaserWeaponArmory(Scene):
def enter(self):
print "You enter into the Laser Weapon Armory. There is dead silence"
print "and no signs of any Gothom. You find the bomb placed in a box"
print "which is secured by a key. Guess the key and gain access to neutron "
print "destruction bomb and move ahead. You will get 3 chances. "
print "-----------"
print "Guess the 3-digit key"
key = "%d%d%d" % (randint(0, 9), randint(0, 9), randint(0, 9))
guess_count = 0
guess = raw_input("[keypad]>")
while guess_count < 3 and guess!= key:
print "That was a wrong guess"
guess_count = 1
print "You have %d chances left" % (3 - guess_count)
if guess_count == key:
print "You have entered the right key and gained access to he neutron"
print "destruction bomb. You grab the bomb and run as fast as you can"
print " to the bridge where you must place it in the right place"
return 'the_bridge'
else:
print "The time is over and the Gothoms bomb up the entire ship and"
print "you die"
return 'death'
class TheBridge(Scene):
def enter(self):
print "You burst onto the bridge with the neutron destruction bomb"
print "and surprise 5 Gothoms who are trying to destroy the ship "
print "They haven't taken their weapons out as they see the bomb"
print "under your arm and are afraid by it as they want to see the"
print "bomb set off. What will you do now - throw the bomb or slowly place the bomb"
action = raw_input(">")
if action == "throw the bomb":
print "In a panic you throw the bomb at the Gothoms and as you try to"
print "escape into the door the Gothoms shot at your back and you are killed."
print "As you die you see a Gothom trying to disarm the bomb and you die"
print "knowing that they will blow up the ship eventually."
return 'death'
elif action == "slowly place the bomb":
print "You inch backward to the door, open it, and then carefully"
print "place the bomb on the floor pointing your blaster at it."
print "Then you immediately shut the door and lock the door so"
print "that the Gothoms can't get out. Now as the bomb is placed"
print "you run to the escape pod to get off this tin can."
return 'escape_pod'
class EscapePod(Scene):
def enter(self):
print "You rush through the whole ship as you try to reach the escape pod"
print "before the ship explodes. You get to the chamber with the escape pods"
print "and now have to get into one to get out of this ship. There are 5 pods"
print "in all and all are marked from 1 to 5. Which escape pod will you choose?"
right_pod = randint(1, 5)
guess = raw_input("[pod#]>")
if int(guess) != right_pod:
print "You jump into the %s pod and hit the eject button" % guess
print "The pod escape into the void of space, then"
print "implodes as the hull ruptures crushing your"
print "whole body"
return 'death'
elif int(guess) == right_pod:
print "You jump into the %s pod and hit the eject button" % guess
print "The pod easily slides out into the space heading to the planet below"
print "As it flies to the planet you see the ship exploding"
print "You won!"
return "finished"
class Map(object):
scenes = {
'central_corridor' : CentralCorridor(),
'laser_weapon_armory' : LaserWeaponArmory(),
'the_bridge' : TheBridge(),
'escape_pod' : EscapePod(),
'death' : Death()
}
def __init__(self, start_scene):
self.start_scene = start_scene
def next_scene(self, scene_name):
return Map.scenes.get(scene_name)
def opening_scene(self):
return self.next_scene(self.start_scene)
a_map = Map('central_corridor')
a_game = Engine(a_map)
a_game.play()该代码是一个简单的文本冒险游戏，玩家需要通过做出选择来推进游戏进程。但是，当执行此代码时，没有任何输出或错误提示，游戏无法正常运行。
2、解决方案
分析代码可以发现，问题在于没有正确地将 Map 对象传递给 Engine 的构造函数。在代码中，有一个语句：
代码语言：javascript复制a_game = Engine('central_corridor')这里，将 'central_corridor' 字符串作为参数传递给了 Engine 的构造函数，而不是 Map 对象。这导致 Engine 无法正常工作，因为 Map 对象包含了游戏场景之间的关系和当前场景的信息。
因此，解决方案是将 Map 对象作为参数传递给 Engine 的构造函数，而不是字符串。修改后的代码如下：
代码语言：javascript复制a_game = Engine(a_map)运行修改后的代码后，游戏可以正常运行，玩家可以做出选择来推进游戏进程。
代码例子
代码语言：javascript复制class Scene(object):
def enter(self):
print("This is not yet configured. Subclass it and implement enter")
exit(1)
class Engine(object):
def __init__(self, scene_map):
self.scene_map = scene_map
def play(self):
current_scene = self.scene_map.opening_scene()
while True:
print("n-------------")
next_scene_name = current_scene.enter()
current_scene = self.scene在解决 Python 代码执行失败时，关键是了解错误的类型并根据错误信息逐步调试。以下步骤可以帮助我们快速解决问题：
- 阅读错误信息：错误信息通常非常明确，会指出错误的类型和发生位置。
- 使用调试工具：通过使用
print()、pdb（Python 调试器）等工具，逐步定位问题。 - 检查环境配置：确保 Python 版本和依赖项正确。
- 逐步缩小问题范围：如果代码复杂，可以先将其简化，确保核心部分能够正常运行，然后再逐步添加功能。
通过这些步骤，你可以更好地理解和解决 Python 代码中的问题。
