9th step for python:exception && assert && import module && Package && publish module && use pip ins

1. exception

try:

    num = int(input("请输入一个整数"))

    result = 8 / num

    print(result)

except ZeroDivisionError :

    print("不可以输入零")

except ValueError :

    print("请勿输入除整数外的字符")

except Exception as result :    #if we can not find the error ,can do like this 

    print("未知错误 %s"%result)

else : #if there is no exception ,will be excuted here.anyone exception appreaced , it can never work

finally: #it ignore wether there is a exception ,it must be worked 

2. raise exception

def input_password():

    pwd = input("input password")

    if len(pwd) >=8:

        return pwd

    print("raise exception")

    ex = Exception("password is too short")

    raise ex

try:

    print(input_password())

except Exception as result:

    print(result)

3. assert

def func(num, div):

    assert (div != 0), "input is error 0"# running and check the error,will stop and show this error

    return num / div

print(func(5,0))

4. import:

import module1,module2

import module1 as m1   #when module1's name is too long can called it m1

from module import function_name #if we just need a little functions from a module, we can use this to import it ,and when we use the functions ,need not to use module's name

file: a.py(def aa())

file: b.py

from a.py import aa()

aa()

from a.py import * #it can import the whole function in a.py

if we import two module which the same name function in the two module, the latter function will rewrite the farther one.it can not rewrite after we renamed.

5. __file__

can show where is the file 

import random

import random

if __name__ == "__main__" :

    print (__name__)

  print(random.__file__)

6. __name__

if a module want to text it function or works to show something which need not show for the importer .we can add the "__name__" in the module for text ,"__name__" will be change to "__main__"when the module excuted by itself;will be change to "module_name"

def main() :

    print

if __name__ =="__main__" :#when we can put the text in the main function

    print

7. Package

a Package must need one file :__init__.py , it tells the importer which function can be import

Package_name: h_message

__init__py:

from . import send_message

from . import  receive_message

 receive_message.py:

def receive():

    return "this is come from .."

send_message.py:

def send(text):

    print("%s"%text)

importer:

import h_message

print(h_message.receive_message.receive())

h_message.send_message.send("uk")

8. publish module

create "setup.py" in the directory which include the the Package of list 6 :

 the tree like this: the root dirctory is D:\workplace\publish_mudole_text

setup.py

│

├─.idea

│  │  misc.xml

│  │  modules.xml

│  │  publish_mudole_text.iml

│  │  workspace.xml

│  │

│  └─inspectionProfiles

└─h_message

        receive_message.py

        send_message.py

        __init__.py

setup.py:

from distutils.core import setup

setup(

    name = "h_message",

    version="1.0",

    description="it is send and receive message module",

    author="chis",

    author_email=" [email protected] ",

    url="chistoiy.top",

    py_modules=["h_message.send_message",

                "h_message.receive_message"]

)

after setup.py:

D:\workplace\publish_mudole_text>python36 setup.py build

D:.

│  setup.py

│

├─.idea

│  │  misc.xml

│  │  modules.xml

│  │  publish_mudole_text.iml

│  │  workspace.xml

│  │

│  └─inspectionProfiles

├─ build

│  └─lib

│      └─h_message

│              receive_message.py

│              send_message.py

│              __init__.py

│

└─h_message

        receive_message.py

        send_message.py

        __init__.py

after this:

D:\workplace\publish_mudole_text>python36 setup.py sdist

the dirctory is :

D:\workplace\publish_mudole_text>tree /f

卷 系统 的文件夹 PATH 列表

卷序列号为 2D07-64DF

D:.

│  MANIFEST

│  setup.py

│

├─.idea

│  │  misc.xml

│  │  modules.xml

│  │  publish_mudole_text.iml

│  │  workspace.xml

│  │

│  └─inspectionProfiles

├─build

│  └─lib

│      └─h_message

│              receive_message.py

│              send_message.py

│              __init__.py

│

├─ dist

│      h_message-1.0.tar.gz

│

└─h_message

        receive_message.py

        send_message.py

        __init__.py

if we want to install this tar.gz module:

python36 setup.py install

>>> import h_message as h

>>> h.send_message("nihao")

Traceback (most recent call last):

  File "<stdin>", line 1, in <module>

TypeError: 'module' object is not callable

>>> h.send_message.send("nihao")

nihao

uninstall this module：

>>> print(h_message.__file__)

D:\workplace\publish_mudole_text\dist\h_message-1.0\h_message-1.0\h_message \__init__.py

delete this dictory is ok.

9. pip install module

in linux:

for 2.x:

pip install module_name

pip uninstall module_name

for 3.x:

pip3 install module_name

pip3 install module_name

pip list#to show the list of module