Python imports functions that reference other files (continuously updated)

Construct the initialization file structure, take this as an example.

Three-level file structure

• Among them, folders A and B are at the same level as files c and d.
• Files a and b are at the same level.
• In order to facilitate testing, the contents of the initialization files a, b, c, d are as follows.
• In-file functions are used for test output.

• Different situations are explained below

【1】Function to import other files in the same directory and at the same level ( c.py文件导入d.py文件的函数)

（1）只引入d.py文件

import d

def functionC():
    print("引入functionC")
d.functionD()

• d.functionD() is required when calling functions in d
• You can also rename the imported file d
• Just add an as

import d as newNameD

def functionC():
    print("引入functionC")
newNameD.functionD()

（2）直接引入函数

• Introduce a single function

from d import functionD

def functionC():
    print("引入functionC")
functionD()

（3）引入全部函数

from d import *

def functionC():
    print("引入functionC")
functionD()

【2】Import files in other folders in the same directory but at different levels ( c.py导入A文件夹内的a.py文件的函数)

（1）只引入a.py文件

• Calling a function requires a file name. Function name such as a.functionA()

from A import a

def functionC():
    print("引入functionC")

a.functionA()

（2）直接引入函数

• Just write the function name directly when calling

from A.a import functionA

def functionC():
    print("引入functionC")

functionA()

（3）引入全部函数

from A.a import *

def functionC():
    print("引入functionC")

functionA()

【3】Import files in different directories ( B文件中b.py导入A文件中a.py文件内的函数)

前置条件：

• 【1】Introduce import sys and use sys.path.append(“…/”) to splice the path
• 【2】Set the folder to be imported as Sources Root
• This example sets the A folder as Sources Root
• New -> Mark Directory as -> Sources Root

（1）只引入a.py文件

• Call a.functionA()

import sys
sys.path.append("../A")
import a
def functionB():
    print("引入functionB")
a.functionA()

（2）直接引入函数

import sys
sys.path.append("../A")
from a import functionA 
def functionB():
    print("引入functionB")
functionA()

（3）引入全部函数

import sys
sys.path.append("../A")
from a import *
def functionB():
    print("引入functionB")
functionA()