模块

模块

函数完成一个功能，其他代码用来调用，提供了代码的重用性和代码间的耦合。而对于一个复杂的功能来，可能需要多个函数才能完成（函数又可以在不同的.py文件中），n个.py 文件组成的代码集合就称为模块。

模块的类型

• 自定义模块
• 内置模块
• 开源模块

 一、自定义dj模块

user_main.py文件内容

import sys
print(sys.path)  #全局环境变量
from backend.logic import handle  #导入backend.logic下的handle文件
handle.home()  #执行handle下的home函数

handle.py文件内容

from backend.db.sql_api import select  #导入backend.db.sql_api下的select函数

def home():
    print("welcome to home page")
    q_data =  select("user",'ddd')  #执行select函数
    print("query res:",q_data)
def movie():
    print("welcome to movie page")
def tv():
    print("welcome to tv page")

sql_api.py文件内容

import sys
import os
base_dir = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))  #获取dj的路径
sys.path.append(base_dir)
#print(__file__)  #打印当前程序的路径
#print(os.path.abspath(__file__))  #当前绝对路径
from config import settings

def db_auth(configs):
    if configs.DATABASE["user"] == 'root' and configs.DATABASE["password"] == '123':
        print("db authentication passed!")
        return True
    else:
        print("db login error...")

def select(table,column):

    if db_auth(settings):
        if table == 'user':
            user_info = {
                "001":['yoyo',22,'engineer'],
                "002": ['nima', 49, 'chef'],
                "003": ['nimei', 18, '13baoan'],
            }
            return user_info

settings.py文件

DATABASE = {
    "engine":"mysql",
    "host":"localhost",
    "port":3306,
    "user":"root",
    "password":"123"
}

二、开源模块

安装和使用

开源模块的上传下载地址：https://pypi.python.org/pypi/

使用pip下载 c:program filespython35scripts>pip3.5.exe install openunipay

三、内置模块

1.pickle与json

用于序列化，两者的区别

• pickle：Python专有，Python数据类型转换，只能用于Python之间
• json：可用于任何语言之间的数据类型转换

pickle

一个文件进行序列化
import pickle
f = open("test.txt","wb")
info  = {
    "nima":"22",
    "nimei":"25"
}
print(pickle.dumps(info))
f.write(pickle.dumps(info))
f.close()

另一个文件进行反序列化
import pickle
f = open("test.txt","rb")
a = pickle.loads(f.read())
print(a)

#输出结果{'nima': '22', 'nimei': '25'}

json

f = open("test.txt","w")
info ={
    "nima":"22",
    "nimei":"25"
}
f.write(json.dumps(info))
f.close()

f = open("test.txt","r")
a = json.loads(f.read())
print(a)

 2.shutil

高级的 文件、文件夹、压缩包 处理模块

import shutil

shutil.copyfileobj(fsrc, fdst[, length])，将文件内容拷贝到另一个文件中，可以部分内容

shutil.copyfile(src, dst)，拷贝文件

shutil.copymode(src, dst)，仅拷贝权限。内容、组、用户均不变

shutil.copystat(src, dst)，拷贝状态的信息，包括：mode bits, atime, mtime, flags

shutil.copy(src, dst)，拷贝文件和权限

shutil.copy2(src, dst)，拷贝文件和状态信息

shutil.ignore_patterns(*patterns)
shutil.copytree(src, dst, symlinks=False, ignore=None)，递归的去拷贝文件

shutil.rmtree(path[, ignore_errors[, onerror]])，递归的去删除文件

shutil.move(src, dst)，递归的去移动文件

shutil.make_archive(base_name, format,...)，创建压缩包并返回文件路径

  例子：ret = shutil.make_archive("test", 'gztar', root_dir='/Users/administrator/Downloads/test')

3.hashlib

 用于加密相关的操作，代替了md5模块和sha模块，主要提供 SHA1, SHA224, SHA256, SHA384, SHA512 ，MD5 算法

import hashlib

hash = hashlib.md5()
hash.update(b"admin")
print(hash.digest())   #二进制格式hash
print(hash.hexdigest())   #16进制格式hash

hash = hashlib.sha1()
hash.update(b'admin')
print(hash.hexdigest())

hash = hashlib.sha256()
hash.update(b'admin')
print(hash.hexdigest())

hash = hashlib.sha384()
hash.update(b'admin')
print(hash.hexdigest())

hash = hashlib.sha512()
hash.update(b'admin')
print(hash.hexdigest())

 hmac 模块，它内部对我们创建 key 和 内容 再进行处理然后再加密

import hmac
h = hmac.new(b"dongwushijie")
h.update(b"nihao")
print(h.hexdigest())

4.logging

日志记录模块

日志的级别

Level	When it’s used
DEBUG	Detailed information, typically of interest only when diagnosing problems.
INFO	Confirmation that things are working as expected.
WARNING	An indication that something unexpected happened, or indicative of some problem in the near future (e.g. ‘disk space low’). The software is still working as expected.
ERROR	Due to a more serious problem, the software has not been able to perform some function.
CRITICAL	A serious error, indicating that the program itself may be unable to continue running.

用法

import logging
logging.warning("aaaaaa")
logging.critical("ddddd")
#输出结果 WARNING:root:aaaaaa
#输出结果 CRITICAL:root:ddddd

把日志写入文件

把日志纪录级别设置为INFO，只有比日志是INFO或比INFO级别更高的日志才会被纪录到文件里

import logging
logging.basicConfig(filename="test.txt",level=logging.INFO)
logging.warning("aaaaaa")
logging.critical("ddddd")

为日志添加上时间

logging.basicConfig(format='%(asctime)s %(message)s',datefmt='%m/%d/%Y %I:%M:%S %p')
logging.warning("aaaaaa")
#输出结果  07/21/2016 10:40:10 AM aaaaaa

同时把log打印在屏幕和文件日志里

#create logger
logger = logging.getLogger('TEST-LOG')
logger.setLevel(logging.DEBUG)

 
# create console handler and set level to debug
ch = logging.StreamHandler()
ch.setLevel(logging.DEBUG)

# create file handler and set level to warning
fh = logging.FileHandler("access.log")
fh.setLevel(logging.WARNING)
# create formatter
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')

# add formatter to ch and fh
ch.setFormatter(formatter)
fh.setFormatter(formatter)

# add ch and fh to logger
logger.addHandler(ch)
logger.addHandler(fh)

# 'application' code
logger.debug('debug message')
logger.info('info message')
logger.warn('warn message')
logger.error('error message')
logger.critical('critical message')

5.time

import time
print (time.time())
print (time.mktime(time.localtime()))
print (time.gmtime())
print (time.localtime())
print (time.strptime('2014-11-11', '%Y-%m-%d'))

print (time.strftime('%Y-%m-%d'))  #2016-07-21
print (time.strftime('%Y-%m-%d',time.localtime()))
print (time.asctime())  #Thu Jul 21 10:55:35 2016
print (time.asctime(time.localtime()))  #Thu Jul 21 10:55:35 2016
print (time.ctime(time.time()))  #Thu Jul 21 10:55:35 2016

import datetime
print (datetime.datetime.now())  #2016-07-21 10:55:35.321624

6.shelve

shelve模块是一个简单的k,v将内存数据通过文件持久化的模块，可以持久化任何pickle可支持的python数据格式

import shelve

d = shelve.open('shelve_test') #打开一个文件

class Test(object):
    def __init__(self,n):
        self.n = n


t = Test(123)
t2 = Test(123334)

name = ["alex","rain","test"]
d["test"] = name #持久化列表
d["t1"] = t      #持久化类
d["t2"] = t2

d.close()

>>> import shelve
>>> a = shelve.open("shelve_test")
>>> dir(a)
>>> a.get("test")
['alex', 'rain', 'test']
>>> a.get("t1")
<shelve模块.Test object at 0x026C73B0>
>>> b = a.get("t1")
>>> b
<shelve模块.Test object at 0x026C7350>
>>> b2 = a.get("t2")
>>> b2.n
123334

7.ConfigParser

用于生成和修改常见配置文档

import configparser

config = configparser.ConfigParser()
config["DEFAULT"] = {'ServerAliveInterval': '45',
                      'Compression': 'yes',
                     'CompressionLevel': '9'}

config['bitbucket.org'] = {}
config['bitbucket.org']['User'] = 'hg'
config['topsecret.server.com'] = {}
topsecret = config['topsecret.server.com']
topsecret['Host Port'] = '50022'     # mutates the parser
topsecret['ForwardX11'] = 'no'  # same here
config['DEFAULT']['ForwardX11'] = 'yes'
with open('example.ini', 'w') as configfile:
   config.write(configfile)

生成一个example.ini文件，如下

[DEFAULT]
compression = yes
compressionlevel = 9
serveraliveinterval = 45
forwardx11 = yes

[bitbucket.org]
user = hg

[topsecret.server.com]
host port = 50022
forwardx11 = no

读取example.ini文件

>>> import configparser
>>> config = configparser.ConfigParser()
>>> config.sections()
[]
>>> config.read('example.ini')
['example.ini']
>>> config.sections()
['bitbucket.org', 'topsecret.server.com']
>>> 'bitbucket.org' in config
True
>>> 'bytebong.com' in config
False
>>> config['bitbucket.org']['User']
'hg'
>>> config['DEFAULT']['Compression']
'yes'
>>> topsecret = config['topsecret.server.com']
>>> topsecret['ForwardX11']
'no'
>>> topsecret['Port']
'50022'
>>> for key in config['bitbucket.org']: print(key)
...
user
compressionlevel
serveraliveinterval
compression
forwardx11
>>> config['bitbucket.org']['ForwardX11']
'yes'

增删改查

import configparser

config = configparser.ConfigParser()
config.read('example.ini')

options = config.options('bitbucket.org')
print (options)

sec = config.remove_section('bitbucket.org')
config.write(open('i.cfg', "w"))

config.remove_option('bitbucket.org','user')
config.write(open('i.cfg', "w"))