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Question

我正在为夏季课学习Python，并且遇到了这个错误：在下面的代码中你会看到我有一个包加载到Director.py中，我将其用作我的主文件。但是，当BluePrints.py明显位于目录中时，它将丢失。我也多次检查输入错误，但这不是问题。我正在学习的书中没有关于这个问题的文档，我在网上的Python文档中看不到任何文档，并且在StackOverflow上找不到这个特定的问题。这是我的代码：

# Director.py
from Builder import HouseBuilders as hb, HouseBuilderInterface as hbi 

interface = hbi.HouseBuilderInterface()   # An interface to my concrete builders
first_house = hb.EarthHomeBuilder()   # Initialize a concrete builder

interface.build_room(first_house, 'kitchen')  # Build a room in the Earth House

生成器/ HouseBuilderInterface.py

class HouseBuilderInterface():

    """ HouseBuilder utilizes Python's duck-typing to provide an interface to the concrete house builders"""
    def build_room(obj, room_type):     # Rooms are an attribute shared by all houses
        obj.build_room(room_type)

    def build_wall(obj, room1, room2):  # Walls are an attribute shared by all houses; Duplex's will have a unique Dividing Wall
        obj.build_wall(room1, room2)

    def build_window(obj, wall):        # Windows are an attribute shared by all houses
        obj.build_window(wall)

    def build_door(obj):                # Doors are an attribute shared by all houses; Colonial and Split-level houses can have basement doors
        obj.build_door()

    def build_stairs(obj):              # Stairs can only be built in Colonial and Split-level houses; Colonial stair cases are bigger
        obj.build_stairs()

    def build_extra(obj):               # Some houses have extra features: Earth-homes have plants on the roof, Single-story has a wrap-around-porch, etc.
        obj.build_extra()

生成器/ HouseBuilders.py

import BluePrints

class EarthHomeBuilder():

    def __init__(self):     # Initialize a simple house
        self.room_no = 0
        self.window_no = 0
        self.door_no = 1
        self.wall_no = 4
        self.key = 0                # key attribute is a unique key for the dictionary
        self.house_features = {}

    def build_room(self, room_type):
        new_room = BluePrints.Room(room_type)
        self.room_no += 1
        self.house_features[key] = room_type + ''
        self.key += 1

生成器/ BluePrints.py

class Room():
    """ Defines a room object with an attribute of room_type"""
    def __init__(self, room_type):
        self.room_type = room_type

class Wall():
    """ Defines a Wall object with attributes of window and door """
    def __init__(self):     # Initialize windows & doors to 0 
        self.windows = 0
        self.doors = 0

    def add_window(self):
        self.windows += 1

    def add_door(self):
        self.doors += 1

class Window():
    """ Defines a Window object with no attributes; Adds a window to specified Wall object"""
    def __init__(wall_location):
        wall_location.add_window()      # Use duck-typing to call Wall method add_window()

class Door():
    """ Defines a Door object with no attributes; Adds a door to specified Wall object """
    def __init__(wall_location):
        wall_location.add_door()        # Use duck-typing to call Wall method add_door()

class StairCase():
    """ Defines a StairCase object with an attribute of length """
    def __init__(self, length):
        self.length = length

class ExtraFeature():
    """ Defines an ExtraFeature object which is unique type of house feature specific to each house """
    def __init__(self, extra_feature):
        self.extra_feature = extra_feature

注意：此分配是Builder软件模式的实现。另外，我只测试了build_room方法，如Director.py文件中所示。我不关心任何错误，除非它们涉及导入BluePrints.py的问题确切的错误消息是ImportError：没有名为'BluePrints'的模块

编辑：

我正在使用Python3.4

Answer 1

问题是，在将HouseBuilders导入Director.py之后，sys.path仍然保留在Director.py的目录中，因此没有BluePrints.py直接在sys.path指定的任何目录中。

在尝试查找要导入的包或类时，python会查找sys.path。另外我猜你正在使用Python 3.x。

修复方法是执行documentation所说的内容 -

6.4.2。包内参考

当包被组织成子包时（与示例中的声音包一样），您可以使用绝对导入来引用兄弟包的子模块。例如，如果模块sound.filters.vocoder需要在sound.effects包中使用echo模块，它可以使用sound.effects import echo。

所以在Builder/HouseBuilders.py中，将导入语句更改为 -

from Builder import BluePrints

导入错误：没有名为'BluePrints'的模块

编辑：

1 个答案: