文成小盆友python-num7 -常用模块补充 ，python 牛逼的面相对象
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常用模块的补充
python面相对象
一。常用模块补充
1.configparser模块
configparser 用于处理特定格式的文件，起内部是调用open（）来实现的，他的使用场景是操作特定格式的文件。
特定的格式如下：
＃ [section1] ＃节点名称 k1 = v1 ＃值1 k2 = v2 ＃值2 [section2] ＃节点名称 k1 = v1 ＃值
- 获取文件中的所有节点
##configparser 模块使用 #1.获取所有的节点 import configparser config = configparser.ConfigParser() config.read(‘config.txt‘,encoding=‘utf-8‘) ret = config.sections() print(ret) ＃显示如下： [‘section1‘, ‘section2‘] Process finished with exit code 0
- 获取指定节点下的所有键值
import configparser config = configparser.ConfigParser() config.read(‘config.txt‘,encoding=‘utf-8‘) #2.获取指定节点下所有的值对 ret2 = config.items("section1") print(ret2) ＃显示如下： [(‘k1‘, ‘v1‘), (‘k2‘, ‘v2‘)] Process finished with exit code 0
- 获取指定节点下的所有键
import configparser config = configparser.ConfigParser() config.read(‘config.txt‘,encoding=‘utf-8‘) #3获取指定节点下所有的键 ret3 = config.options("section1") print(ret3) ＃显示如下： [‘k1‘, ‘k2‘] Process finished with exit code 0
- 获取指定节点下指定key的值
import configparser config = configparser.ConfigParser() config.read(‘config.txt‘,encoding=‘utf-8‘) # #4.获取指定节点下key的 值 v = config.get(‘section1‘,‘k1‘) print(v) #v = config.getint(‘name‘,‘name‘) # 这种方法也可以获取到值，只是类型不同 #v = config.getfloat(‘name‘,‘name‘) #v = config.getboolean(‘name‘,‘name‘) ＃显示如下： v1 Process finished with exit code 0
- 检查节点是否存在，删除节点，添加节点
import configparser config = configparser.ConfigParser() config.read(‘config.txt‘,encoding=‘utf-8‘) #4.检查,删除,添加节点 #检查 has_sec = config.has_section(‘name‘) print(has_sec) # #添加 config.add_section("test") config.write(open("config.txt","w",encoding=‘utf-8‘)) #删除节点: config.remove_section("test") config.write(open("config.txt","w",encoding=‘utf-8‘))
- 检查删除指定组内的键值对：
import configparser config = configparser.ConfigParser() config.read(‘config.txt‘,encoding=‘utf-8‘) ##检查,删除,设置 指定组内的键值对 #检查 has_opt = config.has_option(‘section1‘, ‘k1‘) print(has_opt) # # 删除 config.remove_option(‘section1‘, ‘k1‘) config.write(open("config.txt","w",encoding=‘utf-8‘)) #设置 config.set(‘section1‘, ‘k10‘, "123") config.write(open("config.txt","w",encoding=‘utf-8‘)
2.上档次的xml模块（可以很屌的写个配置文件）
在电子计算机中，标记指计算机所能理解的信息符号，通过此种标记，计算机之间可以处理包含各种的信息比如文章等。它可以用来标记数据、定义数据类型，允许用户对自己的标记语言进行定义，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：
<data>
<country name="Liechtenstein">
<rank updated="yes">2</rank>
<year>2023</year>
<gdppc>141100</gdppc>
<neighbor direction="E" name="Austria" />
<neighbor direction="W" name="Switzerland" />
</country>
<country name="Singapore">
<rank updated="yes">5</rank>
<year>2026</year>
<gdppc>59900</gdppc>
<neighbor direction="N" name="Malaysia" />
</country>
<country name="Panama">
<rank updated="yes">69</rank>
<year>2026</year>
<gdppc>13600</gdppc>
<neighbor direction="W" name="Costa Rica" />
<neighbor direction="E" name="Colombia" />
</country>
</data>
- 先加载成xml对象
from xml.etree import ElementTree as ET # 先打开文件加载 # 再将字符串解析成xml特殊对象，root代指xml文件的根节点 str_xml = open(‘xo.xml‘, ‘r‘).read() root = ET.XML(str_xml)
from xml.etree import ElementTree as ET # 直接解析xml文件 tree = ET.parse("xo.xml") # 获取xml文件的根节点 root = tree.getroot()
- 在操作xml对象
在mxl标签与标签之间是可以嵌套的，然而对于每个节点的操作功能是相同的，如下的功能都能使用。
class Element: """An XML element. This class is the reference implementation of the Element interface. An element‘s length is its number of subelements. That means if you want to check if an element is truly empty, you should check BOTH its length AND its text attribute. The element tag, attribute names, and attribute values can be either bytes or strings. *tag* is the element name. *attrib* is an optional dictionary containing element attributes. *extra* are additional element attributes given as keyword arguments. Example form: <tag attrib>text<child/>...</tag>tail """ 当前节点的标签名 tag = None """The element‘s name.""" 当前节点的属性 attrib = None """Dictionary of the element‘s attributes.""" 当前节点的内容 text = None """ Text before first subelement. This is either a string or the value None. Note that if there is no text, this attribute may be either None or the empty string, depending on the parser. """ tail = None """ Text after this element‘s end tag, but before the next sibling element‘s start tag. This is either a string or the value None. Note that if there was no text, this attribute may be either None or an empty string, depending on the parser. """ def __init__(self, tag, attrib={}, **extra): if not isinstance(attrib, dict): raise TypeError("attrib must be dict, not %s" % ( attrib.__class__.__name__,)) attrib = attrib.copy() attrib.update(extra) self.tag = tag self.attrib = attrib self._children = [] def __repr__(self): return "<%s %r at %#x>" % (self.__class__.__name__, self.tag, id(self)) def makeelement(self, tag, attrib): 创建一个新节点 """Create a new element with the same type. *tag* is a string containing the element name. *attrib* is a dictionary containing the element attributes. Do not call this method, use the SubElement factory function instead. """ return self.__class__(tag, attrib) def copy(self): """Return copy of current element. This creates a shallow copy. Subelements will be shared with the original tree. """ elem = self.makeelement(self.tag, self.attrib) elem.text = self.text elem.tail = self.tail elem[:] = self return elem def __len__(self): return len(self._children) def __bool__(self): warnings.warn( "The behavior of this method will change in future versions. " "Use specific ‘len(elem)‘ or ‘elem is not None‘ test instead.", FutureWarning, stacklevel=2 ) return len(self._children) != 0 # emulate old behaviour, for now def __getitem__(self, index): return self._children[index] def __setitem__(self, index, element): # if isinstance(index, slice): # for elt in element: # assert iselement(elt) # else: # assert iselement(element) self._children[index] = element def __delitem__(self, index): del self._children[index] def append(self, subelement): 为当前节点追加一个子节点 """Add *subelement* to the end of this element. The new element will appear in document order after the last existing subelement (or directly after the text, if it‘s the first subelement), but before the end tag for this element. """ self._assert_is_element(subelement) self._children.append(subelement) def extend(self, elements): 为当前节点扩展 n 个子节点 """Append subelements from a sequence. *elements* is a sequence with zero or more elements. """ for element in elements: self._assert_is_element(element) self._children.extend(elements) def insert(self, index, subelement): 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 """Insert *subelement* at position *index*.""" self._assert_is_element(subelement) self._children.insert(index, subelement) def _assert_is_element(self, e): # Need to refer to the actual Python implementation, not the # shadowing C implementation. if not isinstance(e, _Element_Py): raise TypeError(‘expected an Element, not %s‘ % type(e).__name__) def remove(self, subelement): 在当前节点在子节点中删除某个节点 """Remove matching subelement. Unlike the find methods, this method compares elements based on identity, NOT ON tag value or contents. To remove subelements by other means, the easiest way is to use a list comprehension to select what elements to keep, and then use slice assignment to update the parent element. ValueError is raised if a matching element could not be found. """ # assert iselement(element) self._children.remove(subelement) def getchildren(self): 获取所有的子节点（废弃） """(Deprecated) Return all subelements. Elements are returned in document order. """ warnings.warn( "This method will be removed in future versions. " "Use ‘list(elem)‘ or iteration over elem instead.", DeprecationWarning, stacklevel=2 ) return self._children def find(self, path, namespaces=None): 获取第一个寻找到的子节点 """Find first matching element by tag name or path. *path* is a string having either an element tag or an XPath, *namespaces* is an optional mapping from namespace prefix to full name. Return the first matching element, or None if no element was found. """ return ElementPath.find(self, path, namespaces) def findtext(self, path, default=None, namespaces=None): 获取第一个寻找到的子节点的内容 """Find text for first matching element by tag name or path. *path* is a string having either an element tag or an XPath, *default* is the value to return if the element was not found, *namespaces* is an optional mapping from namespace prefix to full name. Return text content of first matching element, or default value if none was found. Note that if an element is found having no text content, the empty string is returned. """ return ElementPath.findtext(self, path, default, namespaces) def findall(self, path, namespaces=None): 获取所有的子节点 """Find all matching subelements by tag name or path. *path* is a string having either an element tag or an XPath, *namespaces* is an optional mapping from namespace prefix to full name. Returns list containing all matching elements in document order. """ return ElementPath.findall(self, path, namespaces) def iterfind(self, path, namespaces=None): 获取所有指定的节点，并创建一个迭代器（可以被for循环） """Find all matching subelements by tag name or path. *path* is a string having either an element tag or an XPath, *namespaces* is an optional mapping from namespace prefix to full name. Return an iterable yielding all matching elements in document order. """ return ElementPath.iterfind(self, path, namespaces) def clear(self): 清空节点 """Reset element. This function removes all subelements, clears all attributes, and sets the text and tail attributes to None. """ self.attrib.clear() self._children = [] self.text = self.tail = None def get(self, key, default=None): 获取当前节点的属性值 """Get element attribute. Equivalent to attrib.get, but some implementations may handle this a bit more efficiently. *key* is what attribute to look for, and *default* is what to return if the attribute was not found. Returns a string containing the attribute value, or the default if attribute was not found. """ return self.attrib.get(key, default) def set(self, key, value): 为当前节点设置属性值 """Set element attribute. Equivalent to attrib[key] = value, but some implementations may handle this a bit more efficiently. *key* is what attribute to set, and *value* is the attribute value to set it to. """ self.attrib[key] = value def keys(self): 获取当前节点的所有属性的 key """Get list of attribute names. Names are returned in an arbitrary order, just like an ordinary Python dict. Equivalent to attrib.keys() """ return self.attrib.keys() def items(self): 获取当前节点的所有属性值，每个属性都是一个键值对 """Get element attributes as a sequence. The attributes are returned in arbitrary order. Equivalent to attrib.items(). Return a list of (name, value) tuples. """ return self.attrib.items() def iter(self, tag=None): 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）。 """Create tree iterator. The iterator loops over the element and all subelements in document order, returning all elements with a matching tag. If the tree structure is modified during iteration, new or removed elements may or may not be included. To get a stable set, use the list() function on the iterator, and loop over the resulting list. *tag* is what tags to look for (default is to return all elements) Return an iterator containing all the matching elements. """ if tag == "*": tag = None if tag is None or self.tag == tag: yield self for e in self._children: yield from e.iter(tag) # compatibility def getiterator(self, tag=None): # Change for a DeprecationWarning in 1.4 warnings.warn( "This method will be removed in future versions. " "Use ‘elem.iter()‘ or ‘list(elem.iter())‘ instead.", PendingDeprecationWarning, stacklevel=2 ) return list(self.iter(tag)) def itertext(self): 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）。 """Create text iterator. The iterator loops over the element and all subelements in document order, returning all inner text. """ tag = self.tag if not isinstance(tag, str) and tag is not None: return if self.text: yield self.text for e in self: yield from e.itertext() if e.tail: yield e.tail 节点功能一览表
根据以上功能我们来是使用他具体来操作下
- 遍历xml文档中的内容
from xml.etree import ElementTree as ET 方法一解析 """ # 打开文件，读取XML内容 --打开先读取 str_xml = open(‘xo.xml‘, ‘r‘).read() # 将字符串解析成xml特殊对象，root代指xml文件的根节点 root = ET.XML(str_xml) """ 方法二解析 # 直接解析xml文件 --直接操作文件 tree = ET.parse("xo.xml") # 获取xml文件的根节点 -- root = tree.getroot() ### 操作 #标签为tag # 顶层标签 print(root.tag) # 遍历XML文档的第二层 for child in root: # 第二层节点的标签名称和标签属性 print(child.tag, child.attrib) # 遍历XML文档的第三层 for i in child: # 第二层节点的标签名称和内容 print(i.tag,i.text) #如此循环
遍历制定节点：
from xml.etree import ElementTree as ET 方法一解析 """ # 打开文件，读取XML内容 str_xml = open(‘xo.xml‘, ‘r‘).read() # 将字符串解析成xml特殊对象，root代指xml文件的根节点 root = ET.XML(str_xml) """ 方法二解析 # 直接解析xml文件 tree = ET.parse("xo.xml") # 获取xml文件的根节点 root = tree.getroot() ### 操作 # 顶层标签 print(root.tag) # 遍历XML中所有的year节点 for node in root.iter(‘year‘): # 节点的标签名称和内容 print(node.tag, node.text)
- 改变节点内容：包括修该，删除等
所有对xml对象内容的修该都是直接操作内存中的内容，因此要想改变文件中的内容就得要重新写入了
修该节点的内容：
from xml.etree import ElementTree as ET ############ 解析方式一 ############ # 打开文件，读取XML内容 str_xml = open(‘xo.xml‘, ‘r‘).read() # 将字符串解析成xml特殊对象，root代指xml文件的根节点 root = ET.XML(str_xml) ############ 操作 ############ # 顶层标签 print(root.tag) # 循环所有的year节点 for node in root.iter(‘year‘): # 将year节点中的内容自增一 new_year = int(node.text) + 1 node.text = str(new_year) # 设置属性 node.set(‘name‘, ‘alex‘) node.set(‘age‘, ‘18‘) # 删除属性 del node.attrib[‘name‘] 保存文件 tree = ET.ElementTree(root) tree.write("newnew.xml", encoding=‘utf-8‘)
from xml.etree import ElementTree as ET ############ 解析方式二 ############ # 直接解析xml文件 tree = ET.parse("xo.xml") # 获取xml文件的根节点 root = tree.getroot() ############ 操作 ############ # 顶层标签 print(root.tag) # 循环所有的year节点 for node in root.iter(‘year‘): # 将year节点中的内容自增一 new_year = int(node.text) + 1 node.text = str(new_year) # 设置属性 node.set(‘name‘, ‘alex‘) node.set(‘age‘, ‘18‘) # 删除属性 del node.attrib[‘name‘] ############ 保存文件 ############ tree.write("newnew.xml", encoding=‘utf-8‘)
删除节点操作
from xml.etree import ElementTree as ET ############ 解析字符串方式打开 ############ # 打开文件，读取XML内容 str_xml = open(‘xo.xml‘, ‘r‘).read() # 将字符串解析成xml特殊对象，root代指xml文件的根节点 root = ET.XML(str_xml) 操作 # 顶层标签 print(root.tag) # 遍历data下的所有country节点 for country in root.findall(‘country‘): # 获取每一个country节点下rank节点的内容 rank = int(country.find(‘rank‘).text) if rank > 50: # 删除指定country节点 root.remove(country) 保存文件 tree = ET.ElementTree(root) tree.write("newnew.xml", encoding=‘utf-8‘)
from xml.etree import ElementTree as ET 解析文件方式 # 直接解析xml文件 tree = ET.parse("xo.xml") # 获取xml文件的根节点 root = tree.getroot() 操作 # 顶层标签 print(root.tag) # 遍历data下的所有country节点 for country in root.findall(‘country‘): # 获取每一个country节点下rank节点的内容 rank = int(country.find(‘rank‘).text) if rank > 50: # 删除指定country节点 root.remove(country) 保存文件 tree.write("newnew.xml", encoding=‘utf-8‘) 解析文件方式打开，删除，保存
创建xml文档
from xml.etree import ElementTree as ET # 创建根节点 root = ET.Element("famliy") # 创建节点大儿子 son1 = ET.Element(‘son‘, {‘name‘: ‘儿1‘}) # 创建小儿子 son2 = ET.Element(‘son‘, {"name": ‘儿2‘}) # 在大儿子中创建两个孙子 grandson1 = ET.Element(‘grandson‘, {‘name‘: ‘儿11‘}) grandson2 = ET.Element(‘grandson‘, {‘name‘: ‘儿12‘}) son1.append(grandson1) son1.append(grandson2) # 把儿子添加到根节点中 root.append(son1) root.append(son1) tree = ET.ElementTree(root) tree.write(‘oooo.xml‘,encoding=‘utf-8‘, short_empty_elements=False) 创建方式（一）
from xml.etree import ElementTree as ET # 创建根节点 root = ET.Element("famliy") # 创建大儿子 # son1 = ET.Element(‘son‘, {‘name‘: ‘儿1‘}) son1 = root.makeelement(‘son‘, {‘name‘: ‘儿1‘}) # 创建小儿子 # son2 = ET.Element(‘son‘, {"name": ‘儿2‘}) son2 = root.makeelement(‘son‘, {"name": ‘儿2‘}) # 在大儿子中创建两个孙子 # grandson1 = ET.Element(‘grandson‘, {‘name‘: ‘儿11‘}) grandson1 = son1.makeelement(‘grandson‘, {‘name‘: ‘儿11‘}) # grandson2 = ET.Element(‘grandson‘, {‘name‘: ‘儿12‘}) grandson2 = son1.makeelement(‘grandson‘, {‘name‘: ‘儿12‘}) son1.append(grandson1) son1.append(grandson2) # 把儿子添加到根节点中 root.append(son1) root.append(son1) tree = ET.ElementTree(root) tree.write(‘oooo.xml‘,encoding=‘utf-8‘, short_empty_elements=False) 创建方式（二）
from xml.etree import ElementTree as ET # 创建根节点 root = ET.Element("famliy") # 创建节点大儿子 son1 = ET.SubElement(root, "son", attrib={‘name‘: ‘儿1‘}) # 创建小儿子 son2 = ET.SubElement(root, "son", attrib={"name": "儿2"
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