modules and imports

.gitignore

@@ -1 +1,3 @@
-.venv
+.venv
+__pycache__/
+*.pyc

src/basic/file1.py

@@ -0,0 +1,28 @@
+
+# All functions, variables, class are available from export
+# Python exports everything(functions, variables, classes) by default
+# See file3 for custome Exporting
+from file3 import *
+
+
+def print_my_name():
+    print("Anikuttan")
+
+
+file1_variable = 30
+
+
+class Ani:
+    pass
+
+
+# ==================================================================
+
+
+print_my_full_name()
+
+hidden_function()  # hidden_function" is not defined error
+
+print(my_name)
+
+nai = AniKuttan()

src/basic/file2.py

@@ -0,0 +1,35 @@
+
+
+# Import the whole module
+# We must use the module name as a prefix
+import file1
+
+file1.print_my_name()
+print(file1.file1_variable)
+
+# ==================================================================
+
+# Import specific functions/variables
+# No prefix needed
+
+from file1 import print_my_name
+
+print_my_name()
+
+# ==================================================================
+
+# Import with alias
+
+import file1 as my_file
+
+my_file.print_my_name()
+
+#==================================================================
+
+# Import all
+from file1 import *
+
+print_my_name()
+file1_variable
+
+my = Ani()

src/basic/file3.py

@@ -0,0 +1,16 @@
+__all__ = ["print_my_full_name", "my_name", "AniKuttan"]
+
+
+def print_my_full_name():
+    print("Anikuttan Vijayakumar from file3.py")
+
+
+my_name = "ANIKUTTAN from file3.py"
+
+
+def hidden_function():
+    print("You shouldn't see me")
+
+
+class AniKuttan:
+    pass

src/basic/file4.py

@@ -0,0 +1,12 @@
+# Here we are importing the function from the service module
+# services is the module (package) name order_service is the file name
+# package is a folder with multiple .py files and an __init__.py file
+from services.order_service import my_order_one
+from services.product_service import helper_product_from_product_file
+from services import my_product_one
+
+# from services import helper_product_from_product_file
+
+# my_order_one()
+my_product_one()
+helper_product_from_product_file()

src/basic/functions.py

@@ -115,3 +115,15 @@ def add(a, b) -> int:
 
 number = add(a=10, b=20)
 print(number)
+
+
+def say_name():
+    ...
+
+
+def say_name():
+    pass
+
+
+v = 10
+dn = 40

src/basic/loops.py

@@ -64,15 +64,15 @@
 #         print(x, y)
 
 
-# students = [{
+students = [{
-#     "name": "Ani",
+    "name": "Ani",
-#     "subject": "Tamil"
+    "subject": "Tamil"
 
-# }, {
+}, {
-#     "name": "Kuttan",
+    "name": "Kuttan",
-#     "subject": "English"
+    "subject": "English"
 
-# }]
+}]
 
 # for value in students:
 #     print(value['name'])

src/basic/my_script/script_1.py

@@ -0,0 +1,23 @@
+# Example 1
+
+# if i run this file directly the name will call once becaus python will run the file top to bottom
+# so the function call will trigger and it prints my name
+def say_my_name_once():
+    print("Anikuttan example 1")
+    print(__name__)
+
+
+say_my_name_once()
+
+# -----------------------------------------------------------------------------------------------------------
+
+# Example 2
+
+
+def say_my_name_once_example2():
+    print("Anikuttan example 2")
+
+
+# see Script_2.py
+if __name__ == "__main__":
+    say_my_name_once()

src/basic/my_script/script_2.py

@@ -0,0 +1,18 @@
+# Example 1
+
+# in here if i run this file script_2.py file it will print my name 2 times
+# because the say_my_name_once triggers first time in this file and 2 time will call from the script_1.py file Example 1
+from script_1 import say_my_name_once_example2
+from script_1 import say_my_name_once
+
+say_my_name_once()
+
+
+# -----------------------------------------------------------
+
+# Example 2
+
+
+say_my_name_once_example2()  # this will call one because the script_1.py file Example 2 there is __name__ condition
+# __name__ will be "__main__" if the file runs directly 
+# if module runs by other file the __name__ will be "own modules name" like script1

src/basic/services/__init__.py

@@ -0,0 +1,16 @@
+# It’s a special file that makes Python treat a directory as a package.
+# it can be empty or we can exports with __all__
+
+from .product_service import my_product_one
+
+__all__ = ["my_product_one"]  # see below
+
+
+# in file4.py the imports look like this
+# 1. from services import my_product_one
+# 2. from services import helper_product_from_product_file # this will give error [cannot import name 'helper_product_from_product_file' from 'services']
+
+# to use helper_product_from_product_file  function or class we can able to access by package name (module name) like
+# ==>  from services.product_service import helper_product_from_product_file
+# But we can able to access the my_product_one function like this
+# ==> from services import my_product_one

src/basic/services/order_service.py

@@ -0,0 +1,6 @@
+def my_order_one():
+    print("This i from order_service.py")
+
+
+def helper_service_from_order_file():
+    print("My service from order service")

src/basic/services/product_service.py

@@ -0,0 +1,8 @@
+# see services/__init__.py file and file4.py
+
+def my_product_one():
+    print("This i from order_service.py -->  my_product_one")
+
+
+def helper_product_from_product_file():
+    print("My service from order service  --> helper_product_from_product_file")