Python之路_Day7-白红宇

Python之路_Day7

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发布时间：2019-06-13

本文共 25154 字，大约阅读时间需要 83 分钟。

Python之路_Day7_课堂笔记

前期回顾

　　一、作业

　　　　1、ATM

　　　　2、计算器

本期内容

　　一、模块

　　　　1、configparser

　　　　2、XML

　　　　3、shutil

　　　　4、subprocess系统命令

　　二、面对对象（上）

　　　　1、面向对象基础

　　　　2、面向对象编程和函数式编程对比

　　　　3、面向对象中对象和类的关系

　　　　4、面向对象之构造方法

　　　　5、面向对象之应用场景实例

　　　　6、面向对象之对象中封装对象

　　　　7、面向对象之单继承

　　　　8、面向对象之多继承

一、模块

1、configparser

用于处理特定格式的文件，其本质上市利用open来操作文件

1 conf文件2 [section1]3 k1 = 1234 k2 = v25 [section2]6 k1 = v1

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 import configparser 5 config = configparser.ConfigParser() 6 config.read("conf",encoding='utf-8') 7 # 获取所有节点 8 ret = config.sections() 9 print(ret)10 # 获取指定节点下所有的键值对11 ret = config.items('section1')12 print(ret)13 # 获取指定节点下所有的建14 ret = config.options('section1')15 print(ret)16 # 获取指定节点下指定key的值17 v = config.get('section1', 'k1')18 # v = config.getint('section1', 'k1')19 # v = config.getfloat('section1', 'k1')20 # v = config.getboolean('section1', 'k1')21 print(v)22 # 检查、删除、添加节点23 # 检查24 has_sec = config.has_section('section1')25 print(has_sec)26 # 添加节点27 config.add_section("SEC_1")28 config.write(open('xxxooo', 'w'))29 # 删除节点30 config.remove_section("SEC_1")31 config.write(open('xxxooo', 'w'))32 # 检查、删除、设置指定组内的键值对33 # 检查34 has_opt = config.has_option('section1', 'k1')35 print(has_opt)36 # 删除37 config.remove_option('section1', 'k1')38 config.write(open('xxxooo', 'w'))39 # 设置40 config.set('section1', 'k10', "123")41 config.write(open('conf', 'w'))

2、XML

XML是实现不同语言或程序之间进行数据交换的协议，XML文件格式如下：

1 class Element:  2     """An XML element.  3     This class is the reference implementation of the Element interface.  4     An element's length is its number of subelements.  That means if you  5     want to check if an element is truly empty, you should check BOTH  6     its length AND its text attribute.  7     The element tag, attribute names, and attribute values can be either  8     bytes or strings.  9     *tag* is the element name.  *attrib* is an optional dictionary containing 10     element attributes. *extra* are additional element attributes given as 11     keyword arguments. 12     Example form: 13         
     
      text
      ...
     tail 14     """ 15     当前节点的标签名 16     tag = None 17     """The element's name.""" 18     当前节点的属性 19     attrib = None 20     """Dictionary of the element's attributes.""" 21     当前节点的内容 22     text = None 23     """ 24     Text before first subelement. This is either a string or the value None. 25     Note that if there is no text, this attribute may be either 26     None or the empty string, depending on the parser. 27     """ 28     tail = None 29     """ 30     Text after this element's end tag, but before the next sibling element's 31     start tag.  This is either a string or the value None.  Note that if there 32     was no text, this attribute may be either None or an empty string, 33     depending on the parser. 34     """ 35     def __init__(self, tag, attrib={}, **extra): 36         if not isinstance(attrib, dict): 37             raise TypeError("attrib must be dict, not %s" % ( 38                 attrib.__class__.__name__,)) 39         attrib = attrib.copy() 40         attrib.update(extra) 41         self.tag = tag 42         self.attrib = attrib 43         self._children = [] 44     def __repr__(self): 45         return "<%s %r at %#x>" % (self.__class__.__name__, self.tag, id(self)) 46     def makeelement(self, tag, attrib): 47         创建一个新节点 48         """Create a new element with the same type. 49         *tag* is a string containing the element name. 50         *attrib* is a dictionary containing the element attributes. 51         Do not call this method, use the SubElement factory function instead. 52         """ 53         return self.__class__(tag, attrib) 54     def copy(self): 55         """Return copy of current element. 56         This creates a shallow copy. Subelements will be shared with the 57         original tree. 58         """ 59         elem = self.makeelement(self.tag, self.attrib) 60         elem.text = self.text 61         elem.tail = self.tail 62         elem[:] = self 63         return elem 64     def __len__(self): 65         return len(self._children) 66     def __bool__(self): 67         warnings.warn( 68             "The behavior of this method will change in future versions.  " 69             "Use specific 'len(elem)' or 'elem is not None' test instead.", 70             FutureWarning, stacklevel=2 71             ) 72         return len(self._children) != 0 # emulate old behaviour, for now 73     def __getitem__(self, index): 74         return self._children[index] 75     def __setitem__(self, index, element): 76         # if isinstance(index, slice): 77         #     for elt in element: 78         #         assert iselement(elt) 79         # else: 80         #     assert iselement(element) 81         self._children[index] = element 82     def __delitem__(self, index): 83         del self._children[index] 84     def append(self, subelement): 85         为当前节点追加一个子节点 86         """Add *subelement* to the end of this element. 87         The new element will appear in document order after the last existing 88         subelement (or directly after the text, if it's the first subelement), 89         but before the end tag for this element. 90         """ 91         self._assert_is_element(subelement) 92         self._children.append(subelement) 93     def extend(self, elements): 94         为当前节点扩展 n 个子节点 95         """Append subelements from a sequence. 96         *elements* is a sequence with zero or more elements. 97         """ 98         for element in elements: 99             self._assert_is_element(element)100         self._children.extend(elements)101     def insert(self, index, subelement):102         在当前节点的子节点中插入某个节点，即：为当前节点创建子节点，然后插入指定位置103         """Insert *subelement* at position *index*."""104         self._assert_is_element(subelement)105         self._children.insert(index, subelement)106     def _assert_is_element(self, e):107         # Need to refer to the actual Python implementation, not the108         # shadowing C implementation.109         if not isinstance(e, _Element_Py):110             raise TypeError('expected an Element, not %s' % type(e).__name__)111     def remove(self, subelement):112         在当前节点在子节点中删除某个节点113         """Remove matching subelement.114         Unlike the find methods, this method compares elements based on115         identity, NOT ON tag value or contents.  To remove subelements by116         other means, the easiest way is to use a list comprehension to117         select what elements to keep, and then use slice assignment to update118         the parent element.119         ValueError is raised if a matching element could not be found.120         """121         # assert iselement(element)122         self._children.remove(subelement)123     def getchildren(self):124         获取所有的子节点（废弃）125         """(Deprecated) Return all subelements.126         Elements are returned in document order.127         """128         warnings.warn(129             "This method will be removed in future versions.  "130             "Use 'list(elem)' or iteration over elem instead.",131             DeprecationWarning, stacklevel=2132             )133         return self._children134     def find(self, path, namespaces=None):135         获取第一个寻找到的子节点136         """Find first matching element by tag name or path.137         *path* is a string having either an element tag or an XPath,138         *namespaces* is an optional mapping from namespace prefix to full name.139         Return the first matching element, or None if no element was found.140         """141         return ElementPath.find(self, path, namespaces)142     def findtext(self, path, default=None, namespaces=None):143         获取第一个寻找到的子节点的内容144         """Find text for first matching element by tag name or path.145         *path* is a string having either an element tag or an XPath,146         *default* is the value to return if the element was not found,147         *namespaces* is an optional mapping from namespace prefix to full name.148         Return text content of first matching element, or default value if149         none was found.  Note that if an element is found having no text150         content, the empty string is returned.151         """152         return ElementPath.findtext(self, path, default, namespaces)153     def findall(self, path, namespaces=None):154         获取所有的子节点155         """Find all matching subelements by tag name or path.156         *path* is a string having either an element tag or an XPath,157         *namespaces* is an optional mapping from namespace prefix to full name.158         Returns list containing all matching elements in document order.159         """160         return ElementPath.findall(self, path, namespaces)161     def iterfind(self, path, namespaces=None):162         获取所有指定的节点，并创建一个迭代器（可以被for循环）163         """Find all matching subelements by tag name or path.164         *path* is a string having either an element tag or an XPath,165         *namespaces* is an optional mapping from namespace prefix to full name.166         Return an iterable yielding all matching elements in document order.167         """168         return ElementPath.iterfind(self, path, namespaces)169     def clear(self):170         清空节点171         """Reset element.172         This function removes all subelements, clears all attributes, and sets173         the text and tail attributes to None.174         """175         self.attrib.clear()176         self._children = []177         self.text = self.tail = None178     def get(self, key, default=None):179         获取当前节点的属性值180         """Get element attribute.181         Equivalent to attrib.get, but some implementations may handle this a182         bit more efficiently.  *key* is what attribute to look for, and183         *default* is what to return if the attribute was not found.184         Returns a string containing the attribute value, or the default if185         attribute was not found.186         """187         return self.attrib.get(key, default)188     def set(self, key, value):189         为当前节点设置属性值190         """Set element attribute.191         Equivalent to attrib[key] = value, but some implementations may handle192         this a bit more efficiently.  *key* is what attribute to set, and193         *value* is the attribute value to set it to.194         """195         self.attrib[key] = value196     def keys(self):197         获取当前节点的所有属性的 key198         """Get list of attribute names.199         Names are returned in an arbitrary order, just like an ordinary200         Python dict.  Equivalent to attrib.keys()201         """202         return self.attrib.keys()203     def items(self):204         获取当前节点的所有属性值，每个属性都是一个键值对205         """Get element attributes as a sequence.206         The attributes are returned in arbitrary order.  Equivalent to207         attrib.items().208         Return a list of (name, value) tuples.209         """210         return self.attrib.items()211     def iter(self, tag=None):212         在当前节点的子孙中根据节点名称寻找所有指定的节点，并返回一个迭代器（可以被for循环）。213         """Create tree iterator.214         The iterator loops over the element and all subelements in document215         order, returning all elements with a matching tag.216         If the tree structure is modified during iteration, new or removed217         elements may or may not be included.  To get a stable set, use the218         list() function on the iterator, and loop over the resulting list.219         *tag* is what tags to look for (default is to return all elements)220         Return an iterator containing all the matching elements.221         """222         if tag == "*":223             tag = None224         if tag is None or self.tag == tag:225             yield self226         for e in self._children:227             yield from e.iter(tag)228     # compatibility229     def getiterator(self, tag=None):230         # Change for a DeprecationWarning in 1.4231         warnings.warn(232             "This method will be removed in future versions.  "233             "Use 'elem.iter()' or 'list(elem.iter())' instead.",234             PendingDeprecationWarning, stacklevel=2235         )236         return list(self.iter(tag))237     def itertext(self):238         在当前节点的子孙中根据节点名称寻找所有指定的节点的内容，并返回一个迭代器（可以被for循环）。239         """Create text iterator.240         The iterator loops over the element and all subelements in document241         order, returning all inner text.242         """243         tag = self.tag244         if not isinstance(tag, str) and tag is not None:245             return246         if self.text:247             yield self.text248         for e in self:249             yield from e.itertext()250             if e.tail:251                 yield e.tail

解析XML

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 from xml.etree import ElementTree as ET 5 tree = ET.parse('xo.xml') 6 root = tree.getroot() 7 for child in root: 8     print(child.tag,child.attrib) 9     for gradechild in child:10         print(gradechild.tag, gradechild.text)

修改节点内容：

由于修改的节点时，均是在内存中进行，其不会影响文件中的内容。所以，如果想要修改，则需要重新将内存中的内容写到文件。

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 from xml.etree import ElementTree as ET 5 ############ 解析方式一 ############ 6 # 打开文件，读取XML内容 7 str_xml = open('xo.xml', 'r').read() 8 # 将字符串解析成xml特殊对象，root代指xml文件的根节点 9 root = ET.XML(str_xml)10 ############ 操作 ############11 # 顶层标签12 print(root.tag)13 # 循环所有的year节点14 for node in root.iter('year'):15     # 将year节点中的内容自增一16     new_year = int(node.text) + 117     node.text = str(new_year)18     # 设置属性19     node.set('name', 'alex')20     node.set('age', '18')21     # 删除属性22     del node.attrib['name']23 ############ 保存文件 ############24 tree = ET.ElementTree(root)25 tree.write("new_xml.xml", encoding='utf-8')

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 from xml.etree import ElementTree as ET 5 ############ 解析方式二 ############ 6 # 直接解析xml文件 7 tree = ET.parse("xo.xml") 8 # 获取xml文件的根节点 9 root = tree.getroot()10 ############ 操作 ############11 # 顶层标签12 print(root.tag)13 # 循环所有的year节点14 for node in root.iter('year'):15     # 将year节点中的内容自增一16     new_year = int(node.text) + 117     node.text = str(new_year)18     # 设置属性19     node.set('name', 'alex')20     node.set('age', '18')21     # 删除属性22     del node.attrib['name']23 ############ 保存文件 ############24 tree.write("new_xml.xml", encoding='utf-8')

创建XML文档

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 from xml.etree import ElementTree as ET 5 # 创建根节点 6 root = ET.Element("famliy") 7 # 创建节点大儿子 8 son1 = ET.Element('son', {
   'name': '儿1'}) 9 # 创建小儿子10 son2 = ET.Element('son', {
   "name": '儿2'})11 # 在大儿子中创建两个孙子12 grandson1 = ET.Element('grandson', {
   'name': '儿11'})13 grandson2 = ET.Element('grandson', {
   'name': '儿12'})14 son1.append(grandson1)15 son1.append(grandson2)16 # 把儿子添加到根节点中17 root.append(son1)18 root.append(son1)19 tree = ET.ElementTree(root)20 tree.write('oooo.xml',encoding='utf-8', short_empty_elements=False)

由于原生保存的XML时默认无缩进，如果想要设置缩进的话，需要修改保存方式：

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 from xml.etree import ElementTree as ET 5 from xml.dom import minidom 6 def prettify(elem): 7     """将节点转换成字符串，并添加缩进。 8     """ 9     rough_string = ET.tostring(elem, 'utf-8')10     reparsed = minidom.parseString(rough_string)11     return reparsed.toprettyxml(indent="\t")12 # 创建根节点13 root = ET.Element("famliy")14 # 创建大儿子15 # son1 = ET.Element('son', {'name': '儿1'})16 son1 = root.makeelement('son', {
   'name': '儿1'})17 # 创建小儿子18 # son2 = ET.Element('son', {"name": '儿2'})19 son2 = root.makeelement('son', {
   "name": '儿2'})20 # 在大儿子中创建两个孙子21 # grandson1 = ET.Element('grandson', {'name': '儿11'})22 grandson1 = son1.makeelement('grandson', {
   'name': '儿11'})23 # grandson2 = ET.Element('grandson', {'name': '儿12'})24 grandson2 = son1.makeelement('grandson', {
   'name': '儿12'})25 son1.append(grandson1)26 son1.append(grandson2)27 # 把儿子添加到根节点中28 root.append(son1)29 root.append(son1)30 raw_str = prettify(root)31 f = open("xxxoo.xml",'w',encoding='utf-8')32 f.write(raw_str)33 f.close()

3、shutil

高级的文件、文件夹、压缩包处理模块

shutil.copyfileobj(fsrc, fdst[, length])

将文件内容拷贝到另一个文件中

1 import shutil2 shutil.copyfileobj(open('old.xml','r'), open('new.xml', 'w'))

shutil.copyfile(src, dst)

拷贝文件

1 shutil.copyfile('f1.log', 'f2.log')

shutil.copymode(src, dst)

仅拷贝权限。内容、组、用户均不变

1 shutil.copymode('f1.log', 'f2.log')

shutil.copystat(src, dst)

仅拷贝状态的信息，包括：mode bits, atime, mtime, flags

1 shutil.copystat('f1.log', 'f2.log')

shutil.copy(src, dst)

拷贝文件和权限

1 import shutil2 shutil.copy('f1.log', 'f2.log')

shutil.copy2(src, dst)

拷贝文件和状态信息

1 import shutil2 shutil.copy2('f1.log', 'f2.log')

shutil.ignore_patterns(*patterns)

shutil.copytree(src, dst, symlinks=False, ignore=None)

递归的去拷贝文件夹

1 import shutil2  3 shutil.copytree('folder1', 'folder2', ignore=shutil.ignore_patterns('*.pyc', 'tmp*'))

shutil.rmtree(path[, ignore_errors[, onerror]])

递归的去删除文件

1 import shutil2 shutil.rmtree('folder1')

shutil.move(src, dst)

递归的去移动文件，它类似mv命令，其实就是重命名。

1 import shutil2 shutil.move('folder1', 'folder3')

shutil.make_archive(base_name, format,...)

创建压缩包并返回文件路径，例如：zip、tar

base_name：压缩包的文件名，也可以是压缩包的路径。只是文件名时，则保存至当前目录，否则保存至指定路径

如：www =>保存至当前路径

如：/Users/wupeiqi/www =>保存至/Users/wupeiqi/

format：压缩包种类，“zip”, “tar”, “bztar”，“gztar”

root_dir：要压缩的文件夹路径（默认当前目录）

owner：用户，默认当前用户

group：组，默认当前组

logger：用于记录日志，通常是logging.Logger对象

1 #将 /Users/wupeiqi/Downloads/test 下的文件打包放置当前程序目录2 import shutil3 ret = shutil.make_archive("wwwwwwwwww", 'gztar', root_dir='/Users/wupeiqi/Downloads/test')4   5   6 #将 /Users/wupeiqi/Downloads/test 下的文件打包放置 /Users/wupeiqi/目录7 import shutil8 ret = shutil.make_archive("/Users/wupeiqi/wwwwwwwwww", 'gztar', root_dir='/Users/wupeiqi/Downloads/test')

shutil 对压缩包的处理是调用 ZipFile 和 TarFile 两个模块来进行的，详细：

　　zipfile

处理zip文件的模块

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 import zipfile 5 # 压缩文件 6 z = zipfile.ZipFile('test_zip.zip', 'w') 7 z.write('conf') 8 z.write('config.py') 9 z.close()10 # 解压文件11 z = zipfile.ZipFile('test_zip.zip', 'r')12 # z.extractall()    # 解压全部文件13 for item in z.namelist():14     print(item)15 z.extract('conf')   # 解压单个文件16 z.close()

　　tarfiel

处理tar文件的模块

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 import tarfile 5 # 压缩 6 tar = tarfile.open('test_tar.tar','w') 7 tar.add("E:\\Python\\oldboy_py\\Day7\\xml_1.py", arcname='xml_test1.py') 8 tar.add("E:\\Python\\oldboy_py\\Day7\\xml_2.py", arcname='xml_test2.py') 9 tar.close()10 # 解压11 tar = tarfile.open('test_tar.tar','r')12 tar.extractall()  # 可设置解压地址,全部解压13 for item in tar.getmembers():14     print(item)15 obj = tar.getmember('xml_test1.py')16 tar.extract(obj)17 tar.close()

4、系统命令subprocess

可以执行shell命令的相关模块和函数有：

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 import subprocess 5 # call 6 # 执行命令，返回状态码 7 ret = subprocess.call(["ls", "-l"], shell=False) 8 ret = subprocess.call("ls -l", shell=True) 9 # check_call10 # 执行命令，如果执行状态码是 0 ，则返回0，否则抛异常11 subprocess.check_call(["ls", "-l"])12 subprocess.check_call("exit 1", shell=True)13 # check_output14 # 执行命令，如果状态码是 0 ，则返回执行结果，否则抛异常15 subprocess.check_output(["echo", "Hello World!"])16 subprocess.check_output("exit 1", shell=True)

subprocess.Popen(...)

用于执行复杂的系统命令

参数：

args：shell命令，可以是字符串或者序列类型（如：list，元组）

bufsize：指定缓冲。0 无缓冲,1 行缓冲,其他缓冲区大小,负值系统缓冲

stdin, stdout, stderr：分别表示程序的标准输入、输出、错误句柄

preexec_fn：只在Unix平台下有效，用于指定一个可执行对象（callable object），它将在子进程运行之前被调用

close_sfs：在windows平台下，如果close_fds被设置为True，则新创建的子进程将不会继承父进程的输入、输出、错误管道。所以不能将close_fds设置为True同时重定向子进程的标准输入、输出与错误(stdin, stdout, stderr)。

shell：同上

env：用于指定子进程的环境变量。如果env = None，子进程的环境变量将从父进程中继承。

universal_newlines：不同系统的换行符不同，True -> 同意使用 \n

startupinfo与createionflags只在windows下有效

将被传递给底层的CreateProcess()函数，用于设置子进程的一些属性，如：主窗口的外观，进程的优先级等等

1 #!/usr/bin/env python2 # -.- coding: utf-8 -.-3 # By sandler4 import subprocess5 # 创建文件夹6 ret1 = subprocess.Popen(["mkdir","t1"])7 ret2 = subprocess.Popen("mkdir t2", shell=True)8 obj = subprocess.Popen("mkdir t3", shell=True, cwd='/home/dev',)

终端输入的命令分为两种：

输入即可得到输出，如：ifconfig

输入进行某环境，依赖再输入，如：python

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 import subprocess 5 obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True) 6 obj.stdin.write("print(1)\n") 7 obj.stdin.write("print(2)") 8 obj.stdin.close() 9 cmd_out = obj.stdout.read()10 obj.stdout.close()11 cmd_error = obj.stderr.read()12 obj.stderr.close()13 print(cmd_out)14 print(cmd_error)15 # 第二种方法16 obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)17 obj.stdin.write("print(1)\n")18 obj.stdin.write("print(2)")19 out_error_list = obj.communicate()20 print(out_error_list)21 # 第三种方法22 obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)23 out_error_list = obj.communicate('print("hello")')24 print(out_error_list)

二、面向对象（上）

什么时候用面向对象？当某一些函数具有相同参数是，可以使用面向对象的方式，将参数值一次性的封装到对象，以后去对象中取值即可。

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 # 面向对象 5 class SQLHelper: 6     def fetch(self,sql): 7         print(self.hhost) 8         print(self.uuser) 9         print(self.ppwd)10         print(sql)11     def create(self,sql):12         print(sql)13     def remove(self,id):14         print(id)15     def modify(self,name):16         print(name)17 obj = SQLHelper()18 obj.hhost = "www.test.com"  # 封装参数19 obj.uuser = "sandler"20 obj.ppwd = "1234"21 obj.fetch('select * from a;')

self到底是个什么鬼？

self是一个python自动会传值的参数

那个对象执行方法，self就是谁

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 # 面向对象 5 class SQLHelper: 6     def __init__(self,host,user,pwd): 7         self.hhost = host  # 封装参数 8         self.uuser = user 9         self.ppwd = pwd10     def fetch(self,sql):11         print(self.hhost)12         print(self.uuser)13         print(self.ppwd)14         print(sql)15     def create(self,sql):16         print(sql)17     def remove(self,id):18         print(id)19     def modify(self,name):20         print(name)21 obj1 = SQLHelper("www.test.com","sandler",1234)22 obj2 = SQLHelper("www.test2.com","sandler",2345)23 obj1.fetch('select * from a;')

面向对象三大特性：封装，继承，多态

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 class c1: 5     def __init__(self,name,obj): 6         self.name = name 7         self.obj = obj 8 class c2: 9     def __init__(self,name,age):10         self.name = name11         self.age = age12     def show(self):13         print(self.name)14 c2_obj = c2('aa' , 11)15 c1_obj = c1('alex',c2_obj)16 print(c1_obj.obj.age)17 print(c1_obj.obj.name)18 print(c1_obj.name)

封装

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 # 面向对象 5 class c1: 6     def __init__(self,name,obj): 7         self.name = name 8         self.obj = obj 9 class c2:10     def __init__(self,name,age):11         self.name = name12         self.age = age13     def show(self):14         print(self.name)15 class c3:16     def __init__(self,a1):17         self.money = 12318         self.aaa = a119 c2_obj = c2('aa' , 11)20 # c2_obj是c2类型21 # - name = 'aa'22 # - age = 1123 c1_obj = c1('alex',c2_obj)24 # c1_obj是c1类型25 # - name = 'alex'26 # - obj = c2_obj27 c3_obj = c3(c1_obj)28 # c3_obj是c3类型29 # - money = 12330 # - aaa = c1_obj31 # 通过c3_obj输出c2内的name32 print(c3_obj.aaa.obj.name)33 # 通过c3_obj输出c2内的show方法34 print(c3_obj.aaa.obj.show())

继承

1 #!/usr/bin/env python 2 # -.- coding: utf-8 -.- 3 # By sandler 4 # 类的继承 5 class F1: 6     def show(self): 7         print('show') 8     def foo(self): 9         print(self.name)10 class F2(F1):11     def __init__(self,name):12         self.name = name13     def bar(self):14         print('bar')15 obj = F2('yuli')16 obj.foo()