Packages and some commonly used modules

What is a bag?

A package is a folder that contains _init_ py files, so the purpose of creating a package is to organize files / modules with folders.

It should be emphasized that:

1. In Python 3, even if there is no _init_ py file under the package, the import package will still not report errors. In Python 2, the file must be under the package, otherwise the import package will report errors.

2. The purpose of creating packages is not to run, but to be imported and used. Remember, packages are only a form of modules, and the essence of packages is a module.

Why use packages

The essence of a package is a folder, so the only function of a folder is to organize the files. As more functions are written, we can't put all the functions into one file. So we use modules to organize the functions. As more modules are built, we need folders to organize the module files. To improve the structure and maintainability of programs

Matters needing attention:

Packet import can also be divided into import and from...import... two kinds, but no matter where it is, it must follow a principle when importing: Whatever points are brought in at the time of import, the left side of the points must be a package, otherwise it is illegal.

First import package:

Generate an execution file namespace first

Create the namespace of the _init_.py file under the package

2. Execute the code in the _init_ py file below the package to place the generated name in the _init_ py file namespace below the package

3. Get a name in the execution file that points to the _init_.py file namespace under the package

Developer Standing on Package: If you use absolute paths to manage your modules, it only needs to import modules in turn based on the path of the package forever.

User standing in the package: You must add the folder path where the package is located to the system path.

logging module

Logging Module: Recording

Logs are divided into five levels

logging.debug() #10

logging.info() #20

logging.warning() #30

logging.error() #40

logging.critical() #50

1.logger object: responsible for generating logs

2.filter object: filter logs (understand)

3.handler Object: Location of Control Log Output (File/Terminal)

4. Formmate object: specify the format of log content

logging Configuration Dictionary

import os
import logging.config

# Define three log output formats to start with

standard_format = '[%(asctime)s][%(threadName)s:%(thread)d][task_id:%(name)s][%(filename)s:%(lineno)d]' \
                  '[%(levelname)s][%(message)s]' #among name by getlogger Designated name

simple_format = '[%(levelname)s][%(asctime)s][%(filename)s:%(lineno)d]%(message)s'
# Define the end of log output format
The values of the following two variables need to be modified manually
logfile_dir = os.path.dirname(__file__)  # log Catalogue of documents
logfile_name = 'a3.log'  # log file name
# If there is no defined log directory, create one
if not os.path.isdir(logfile_dir):
    os.mkdir(logfile_dir)
# log Full path of file
logfile_path = os.path.join(logfile_dir, logfile_name)


# log Configuration Dictionary
LOGGING_DIC = {
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {
        'standard': {
            'format': standard_format
        },
        'simple': {
            'format': simple_format
        },
    },
    'filters': {},  # Filter logs
    'handlers': {
        #Print logs to terminals
        'console': {
            'level': 'DEBUG',
            'class': 'logging.StreamHandler',  # Print to screen
            'formatter': 'simple'
        },
        #Logs printed to files,collect info Logs above
        'default': {
            'level': 'DEBUG',
            'class': 'logging.handlers.RotatingFileHandler',  # Save to file
            'formatter': 'standard',
            'filename': logfile_path,  # log file
            'maxBytes': 1024*1024*5,  # Log size 5 M
            'backupCount': 5,
            'encoding': 'utf-8',  # Log file encoding, no longer need to worry about Chinese log The code is out of order.
        },
    },
    'loggers': {
        #logging.getLogger(__name__)Get it logger To configure
        '': {
            'handlers': ['default', 'console'],  # Here are the two definitions above. handler Add all, that is log Data is written to the file and printed to the screen.
            'level': 'DEBUG',
            'propagate': True,  # Up (higher) level Of logger)transmit
        },  # This is used by default when the key does not exist k:v To configure
    },
}


# Configuration using log dictionary
logging.config.dictConfig(LOGGING_DIC)  # Configuration in Autoloading Dictionary
logger1 = logging.getLogger('asajdjdskaj')
logger1.debug('Good without impetuosity, hard work will bear fruit')

logging Configuration Dictionary

hashlib module

hashlib Module

import hashlib
#The incoming content can be passed in several times, so long as the incoming content is the same, the ciphertext generated must be the same.

md = hashlib.md5()
md.update(b'nihaoma')
md.update(b'ni')
md.update(b'hao')
md.update(b'ma')
print(md.hexdigest())

hashlib Application scenarios of modules
    1.Password Storage
    2.Check the consistency of document content

1. Different algorithms use the same method.

The longer the ciphertext length, the more complex the internal corresponding algorithm is.

however
1. The longer the time consumed
2. Take up more space
Usually, using md5 algorithm is enough.

Salting treatment

Salting treatment
import hashlib

md = hashlib.md5()
//The company itself manually adds some content before each data needs to be encrypted
md.update(b'oldboy.com')  # Salting treatment
md.update(b'hello')  # Real content
print(md.hexdigest())


//Dynamic Salting
import hashlib

def get_md5(data):
    md = hashlib.md5()
    md.update('Salting'.encode('utf-8'))
    md.update(data.encode('utf-8'))
    return md.hexdigest()

password = input('password>>:')
res = get_md5(password)
print(res)

openpyxl Fire Operating Excel Table Module

Before version 03, the suffix name of excel file is xls
After version 03, the suffix name of excel file is xlsx

xlwd writes excel
xlrt reads excel

xlwd and xlrt support both excel files before version 03 and excel files after version 03
openpyxl only supports xlsx after version 03

write
from openpyxl import  Workbook

wb = Workbook()  # Mr. A becomes a workbook
wb1 = wb.creat_sheet('index',0)    # Create a form page that can be digitally controlled at the back
wb1.title = 'login' #Later, you can use form page object points title Modify the form name

wb1['A3'] = 666
wb1['A4'] = 555
wb1.cell(row=6,column=3,value=88888)
wb1[A5'] = '=sum(A3:A4)'
wb1.append(['username','age','hobby'])
wb1.append(['jason',18,'study'])
wb1.append(['tank',72,'Eat raw oysters'])
//Save the new file
wb.save('test.xlsx')


from openpyxl import load_workbook  #read file
wb = load_work('test.xlsx',read_only=True,data_only=True)
print(wb)
print(wb.sheetnames)  # ['login', 'Sheet', 'index1']
print(wb['login']['A3'].value)
print(wb['login']['A4'].value)
print(wb['login']['A5'].value)  # Generated by code excel Tables must be manipulated artificially before they can read the result values calculated by the function.

Deep and shallow copies

l = [1,2,[1,2]]
# l1 = l
# print(id(l),id(l1))
# l1 = copy.copy(l)  # A copy .......  shallow copy
# print(id(l),id(l1))
# # l[0] = 222
# # print(l,l1)
# l[2].append(666)
# print(l,l1)
l1 = copy.deepcopy(l)
l[2].append(666)
print(l,l1)

Programming VIP

Packages and some commonly used modules

Popular Keywords