导入错误:没有名为“BluePrints”的模块

Question

我正在为一个暑期班学习Python，并且遇到了这个错误:在下面的代码中，您将看到我有一个包，我将它加载到Director.py中，我正在使用它作为我的主文件。但是，当BluePrints.py明显位于目录中时，它就会丢失。我也检查了多次打字错误，但这不是问题。在我正在学习的书中，没有关于这个问题的文档，也没有我可以在中看到的文档，也无法在StackOverflow上找到这个特定的问题。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

Builder/Builder BuilderInterface.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()

建筑商/房屋建筑商

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

Builder/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:此作业是Builder软件模式的实现。此外，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，因此在sys.path指定的任何目录中都没有BluePrints.py。

在试图找到要导入的包或类时，python查找的正是sys.path。另外，我猜您正在使用Python3.x。

解决办法是按文档说的去做-

6.4.2.包内引用 当包被构造成子包时(如示例中的声音包)，您可以使用绝对导入来引用兄弟程序包的子模块。例如，如果模块sound.filters.vocoder需要使用sound.effects包中的回显模块，则可以从sound.effects导入回送。

因此，在Builder/HouseBuilders.py中，将导入语句更改为-

from Builder import BluePrints