Question

我有两段Python代码 - 一部分正常，另一部分则出现错误。这是什么规则呢？

以下是产生错误的代码块以及错误：

代码：

elif door == "2": 
    print "You stare into the endless abyss at Cthulhu's retina."
    print "1. blueberries."
    print "2. Yellow jacket clothespins."
    print "3. Understanding revolvers yelling melodies."

    insanity = raw_input("> ")

    if insanity == "1" or insanity == "2": 
        print "Your body survives powered by a mind of jello. Good job!" 
        print "Now what will you do with the jello?"
        print "1. Eat it."
        print "2. Take it out and load it in a gun."
        print "3 Nothing."

        jello = raw_input("> ")

        if jello == "1" or jello == "2":
            print "Your mind is powered by it remember? Now you are   dead!"
        elif jello == "3":
            print "Smart move. You will survive." 
        else:
            print "Do something!" 

else: 
    print "The insanity rots your eyes into a pool of muck. Good job!"

我在提示符中收到此错误消息：

  File "ex31.py", line 29
  print "Now what will you do with the jello?"
                                           ^
IndentationError: unindent does not match any outer indentation level

但是我的代码是这样的：

elif door == "2": 
print "You stare into the endless abyss at Cthulhu's retina."
print "1. blueberries."
print "2. Yellow jacket clothespins."
print "3. Understanding revolvers yelling melodies."

insanity = raw_input("> ")

if insanity == "1" or insanity == "2": 
    print "Your body survives powered by a mind of jello. Good job!" 
        print "Now what will you do with the jello?"
        print "1. Eat it."
        print "2. Take it out and load it in a gun."
        print "3 Nothing."

        jello = raw_input("> ")

        if jello == "1" or jello == "2":
            print "Your mind is powered by it remember? Now you are dead!"
        elif jello == "3":
            print "Smart move. You will survive." 
        else:
            print "Do something!" 

else: 
    print "The insanity rots your eyes into a pool of muck. Good job!"

我没有收到任何错误消息。

基本上我的问题是 - 如果我缩进行

，为什么我不会收到错误消息

print "Now what will you do with the jello?"

...以及其下方代码块的其余部分。

但如果我把它留下与上面一行相同的缩进，我会得到一个错误代码？

这是否意味着if语句后面的打印行只能是一行，没有其他打印行允许链接到该块的第一个打印行上方的if语句的输出？

感谢。

Answer 1

我怀疑你正在混合空格和制表符。最好只使用空格，以便您的视觉缩进与逻辑缩进相匹配。

检查您的源代码，第二行中有一个制表符：

    if insanity == "1" or insanity == "2": 
\t    print "Your body survives powered by a mind of jello. Good job!" 
        print "Now what will you do with the jello?"

我用\t对其进行了标记，这使得混合缩进更加突出。

Answer 2

您在此代码顶部的elif之后没有缩进：

elif door == "2": 
print "You stare into the endless abyss at Cthulhu's retina."
print "1. blueberries."
print "2. Yellow jacket clothespins."
print "3. Understanding revolvers yelling melodies."

你试过了吗？

elif door == "2": 
    print "You stare into the endless abyss at Cthulhu's retina."
    print "1. blueberries."
    print "2. Yellow jacket clothespins."
    print "3. Understanding revolvers yelling melodies."

看看会发生什么？

Answer 3

您是否检查过您的缩进是否一致？你到处使用4个空格（不是制表符）吗？我从第一个例子中剪切并粘贴你的代码（从精神错乱的原始输入开始），它在我的机器上运行正常。

Answer 4

关闭切线：

正如你已经发现的那样，尝试用级联的if-else子句做一个任何大小的故事都会很快变得笨拙。

这是一个快速的状态机实现，可以轻松地逐个房间编写故事：

# assumes Python 3.x:

def get_int(prompt, lo=None, hi=None):
    """
    Prompt user to enter an integer and return the value.

    If lo is specified, value must be >= lo
    If hi is specified, value must be <= hi
    """
    while True:
        try:
            val = int(input(prompt))
            if (lo is None or lo <= val) and (hi is None or val <= hi):
                return val
        except ValueError:
            pass

class State:
    def __init__(self, name, description, choices=None, results=None):
        self.name        = name
        self.description = description
        self.choices     = choices or tuple()
        self.results     = results or tuple()

    def run(self):
        # print room description
        print(self.description)

        if self.choices:
            # display options
            for i,choice in enumerate(self.choices):
                print("{}. {}".format(i+1, choice))
            # get user's response
            i = get_int("> ", 1, len(self.choices)) - 1
            # return the corresponding result
            return self.results[i]    # next state name

class StateMachine:
    def __init__(self):
        self.states = {}

    def add(self, *args):
        state = State(*args)
        self.states[state.name] = state

    def run(self, entry_state_name):
        name = entry_state_name
        while name:
            name = self.states[name].run()

并重写你的故事以使用它

story = StateMachine()

story.add(
    "doors",
    "You are standing in a stuffy room with 3 doors.",
    ("door 1", "door 2",  "door 3"  ),
    ("wolves", "cthulhu", "treasury")
)

story.add(
    "cthulhu",
    "You stare into the endless abyss at Cthulhu's retina.",
    ("blueberries", "yellow jacket clothespins", "understanding revolvers yelling melodies"),
    ("jello",       "jello",                     "muck")
)

story.add(
    "muck",
    "The insanity rots your eyes into a pool of muck. Good job!"
)

story.add(
    "jello",
    "Your body survives, powered by a mind of jello. Good job!\nNow, what will you do with the jello?",
    ("eat it",   "load it into your gun", "nothing"),
    ("no_brain", "no_brain",              "survive")
)

story.add(
    "no_brain",
    "With no brain, your body shuts down; you stop breathing and are soon dead."
)

story.add(
    "survive",
    "Smart move, droolio!"
)

if __name__ == "__main__":
    story.run("doors")

为了进行调试，我向StateMachine添加了一个方法，该方法使用pydot打印格式良好的状态图，

# belongs to class StateMachine
    def _state_graph(self, png_name):
        # requires pydot and Graphviz
        from pydot import Dot, Edge, Node
        from collections import defaultdict

        # create graph
        graph = Dot()
        graph.set_node_defaults(
            fixedsize = "shape",
            width     = 0.8,
            height    = 0.8,
            shape     = "circle",
            style     = "solid"
        )

        # create nodes for known States
        for name in sorted(self.states):
            graph.add_node(Node(name))

        # add unique edges;
        ins  = defaultdict(int)
        outs = defaultdict(int)
        for name,state in self.states.items():
            # get unique transitions
            for res_name in set(state.results):
                # add each unique edge
                graph.add_edge(Edge(name, res_name))
                # keep count of in and out edges
                ins[res_name] += 1
                outs[name]    += 1

        # adjust formatting on nodes having no in or out edges
        for name in self.states:
            node = graph.get_node(name)[0]
            i = ins[name]
            o = outs.get(name, 0)
            if not (i or o):
                # stranded node, no connections
                node.set_shape("octagon")
                node.set_color("crimson")
            elif not i:
                # starting node
                node.set_shape("invtriangle")
                node.set_color("forestgreen")
            elif not o:
                # ending node
                node.set_shape("square")
                node.set_color("goldenrod4")

        # adjust formatting of undefined States
        graph.get_node("node")[0].set_style("dashed")
        for name in self.states:
            graph.get_node(name)[0].set_style("solid")

        graph.write_png(png_name)

并将其称为story._state_graph("test.png")会导致

enter image description here

我希望你觉得它有趣且有用。

下一步要考虑的事情：

房间库存：你可以拿起的东西
玩家库存：您可以使用或放弃的东西
可选选项：如果您的库存中有红色键，则只能解锁红门
可修改的房间：如果您进入幽静的小树林并将其点燃，当您稍后返回时，它应该是一个烧焦的小树林

为什么这一段代码会出现错误，而另一块则不会出现错误？

4 个答案: