模块补充
Posted 琪齐
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内置函数vase()
print(vars())
print(type(vars()),vars())
type()函数是返回传递变量的类型。如果传递变量是字典那么它将返回一个字典类型。
__doc__ # py文件的注释
例：
""" 我是index注释 """ print(__doc__)
__file__ #本身自己文件路径
print(__file__)
__package__ #当前文件 None
#导入的其他文件所在的包，用 . 划分
form 文件路径 import 文件
print(文件.__package__)
__cached__ #缓存 （了解）
__name__
1 from lib import s1 2 form lib import s2 3 4 def execute(): 5 print("执行") 6 s1.f1() 7 s2.f1() 8 #只有 执行 python xx.py 时 if__name__ =="__main__": 否则是文件名 9 10 if __name__ == "__main__": 11 execute()
sys模块
sys.path python默认去根据[]的路径去找到模块
1 import sys 2 print(sys.path.append()) 3 print() 4 5 6 7 import os 8 import sys 9 10 p1 = os.path.dirname(__file__) 11 p2 = "lib" 12 13 my_dir = os.path.join(p1,p2) #拼接起来 14 sys.path.append(my_dir) 15 for i in sys.path: 16 print(i)
json模块
json.dumps与json.loads两个用处：
json.dumps() #将python的python基本数据类型装换成字符串
json.loads用于将字典，列表，元组形式的字符串，转换成相应的字典,列表,元组
1 s = \'{"desc":"invilad-citykey","status":1002}\' #疑式字典的外边用单引号，内部必须要用双引号。 2 l = "[11,22,33,44]" 3 4 import json 5 6 7 # result = json.loads(s) 8 # print(result,type(result) 9 #json.loads用于将字典，列表，元祖形式的字符串，转换成相应的字典，列表，元祖。 ***注意json.losds内部必须用双引号*** 10 11 result = json.loads(l) 12 print(result,type(result)) 13 输出[11, 22, 33, 44] <class \'list\'> 14 15 16 17 18 user_list = ["alex","eric","tomy"] 19 import json 20 21 s = json.dumps(user_list) 22 #json.dumps() #将python的python基本数据类型装换成字符串 23 24 print(s,type(s)) 25 #输出["alex", "eric", "tomy"] <class \'str\'>
了解：json.dump与json.load
import json dic = {\'k1\':123,\'k2\':\'v2\'} json.dump(dic,open(\'db\',\'w\')) #读内容 #字符串转换成字典 r = json.load(open(\'db\',\'r\')) print(r,type(r))
import json dic = {\'k1\':123,\'k2\':456} json.dump(dic,open(\'db\',\'w\')) r = json.load(open(\'db\',\'r\')) print(r,type(r))
requests模块
requests,发送http请求（用python模拟浏览器浏览网页）
1 import requests 2 3 requests = requests.get("http://www.weather.com.cn/adat/sk/101010500.html") #浏览天气 4 requests.encoding = "utf-8" 5 result = requests.text 6 print(result)
http请求和XML实例
检测QQ是否在线：
1 import requests 2 # 使用第三方模块requests发送HTTP请求，或者XML格式内容 3 r = requests.get(\'http://www.webxml.com.cn//webservices/qqOnlineWebService.asmx/qqCheckOnline?qqCode=2218308808\') 4 result = r.text #字符串类型 5 6 from xml.etree import ElementTree as ET 7 #解析XML格式内容 8 #XML接收一个参数：字符串，格式化为特殊的对象 9 node = ET.XML(result) 10 11 #获取内容 12 if node.text == "Y": 13 print("在线") 14 else: 15 print("离线")
查看火车停靠信息：
1 1 import requests 2 2 from xml.etree import ElementTree as ET 3 3 4 4 #使用第三模块requests发送HTTP请求，或者XML格式内容 5 5 r = requests.get(\'http://www.webxml.com.cn/WebServices/TrainTimeWebService.asmx/getDetailInfoByTrainCode?TrainCode=K234&UserID=\') 6 6 result = r.text 7 7 8 8 #解析XML格式内容 9 9 root = ET.XML(result) 10 10 11 11 for node in root.iter(\'TrainDetailInfo\'): 12 12 #print(node.tag, node.attrib) 13 13 print(node.find(\'TrainStation\').text, node.find(\'StartTime\').text) 14 14 #print(node.find(\'TrainStation\').text, node.find(\'StartTime\').text,node.tag,node.attrib)
XML
XML是实现不同语言或程序之间进行数据交换
tag #根节点
attrib #标签属性
find #查找
iter #可迭代的
set #设置属性
defau.xml文件
<data>
<country name="Liechtenstein">
<rank updated="yes">2</rank>
<year age="19" name="alex">2040</year>
<gdppc>141100</gdppc>
<neighbor direction="E" name="Austria" />
<neighbor direction="W" name="Switzerland" />
</country>
<country name="Singapore">
<rank updated="yes">5</rank>
<year age="19" name="alex">2043</year>
<gdppc>59900</gdppc>
<neighbor direction="N" name="Malaysia" />
</country>
</data>
1，解析XML
1）用ElementTree.XML将字符串解析成xml对象：
1 form xml.etree import ElementTree as ET 2 3 str_xml = open(\'defau.xml\', \'r\').read() #打开daefau.xml文件，读取xml内容 4 5 root = ET.XML(str_xml) #将支付串解析成xml对象，root指代xml文件节点
2）用ElementTree.parse将文件直接解析成xml对象
1 form xml.etree import ElementTree as ET 2 3 tree = ET.parse("defau.xml") #直接解析xml文件 4 5 root = tree.getroot() #获取xml文件节点
2，XML操作
xml格式类型是节点嵌套节点，对于每个节点均可操作。
1 class Element: 2 """An XML element. 3 4 This class is the reference implementation of the Element interface. 5 6 An element\'s length is its number of subelements. That means if you 7 want to check if an element is truly empty, you should check BOTH 8 its length AND its text attribute. 9 10 The element tag, attribute names, and attribute values can be either 11 bytes or strings. 12 13 *tag* is the element name. *attrib* is an optional dictionary containing 14 element attributes. *extra* are additional element attributes given as 15 keyword arguments. 16 17 Example form: 18 <tag attrib>text<child/>...</tag>tail 19 20 """ 21 22 当前节点的标签名 23 tag = None 24 """The element\'s name.""" 25 26 当前节点的属性 27 28 attrib = None 29 """Dictionary of the element\'s attributes.""" 30 31 当前节点的内容 32 text = None 33 """ 34 Text before first subelement. This is either a string or the value None. 35 Note that if there is no text, this attribute may be either 36 None or the empty string, depending on the parser. 37 38 """ 39 40 tail = None 41 """ 42 Text after this element\'s end tag, but before the next sibling element\'s 43 start tag. This is either a string or the value None. Note that if there 44 was no text, this attribute may be either None or an empty string, 45 depending on the parser. 46 47 """ 48 49 def __init__(self, tag, attrib={}, **extra): 50 if not isinstance(attrib, dict): 51 raise TypeError("attrib must be dict, not %s" % ( 52 attrib.__class__.__name__,)) 53 attrib = attrib.copy() 54 attrib.update(extra) 55 self.tag = tag 56 self.attrib = attrib 57 self._children = [] 58 59 def __repr__(self): 60 return "<%s %r at %#x>" % (self.__class__.__name__, self.tag, id(self)) 61 62 def makeelement(self, tag, attrib): 63 创建一个新节点 64 """Create a new element with the same type. 65 66 *tag* is a string containing the element name. 67 *attrib* is a dictionary containing the element attributes. 68 69 Do not call this method, use the SubElement factory function instead. 70 71 """ 72 return self.__class__(tag, attrib) 73 74 def copy(self): 75 """Return copy of current element. 76 77 This creates a shallow copy. Subelements will be shared with the 78 original tree. 79 80 """ 81 elem = self.makeelement(self.tag, self.attrib) 82 elem.text = self.text 83 elem.tail = self.tail 84 elem[:] = self 85 return elem 86 87 def __len__(self): 88 return len(self._children) 89 90 def __bool__(self): 91 warnings.warn( 92 "The behavior of this method will change in future versions. " 93 "Use specific \'len(elem)\' or \'elem is not None\' test instead.", 94 FutureWarning, stacklevel=2 95 ) 96 return len(self._children) != 0 # emulate old behaviour, for now 97 98 def __getitem__(self, index): 99 return self._children[index] 100 101 def __setitem__(self, index, element): 102 # if isinstance(index, slice): 103 # for elt in element: 104 # assert iselement(elt) 105 # else: 106 # assert iselement(element) 107 self._children[index] = element 108 109 def __delitem__(self, index): 110 del self._children[index] 111 112 def append(self, subelement): 113 为当前节点追加一个子节点 114 """Add *subelement* to the end of this element. 115 116 The new element will appear in document order after the last existing 117 subelement (or directly after the text, if it\'s the first subelement), 118 but before the end tag for this element. 119 120 """ 121 self._assert_is_element(subelement) 122 self._children.append(subelement) 123 124 def extend(self, elements): 125 为当前节点扩展 n 个子节点 126 """Append subelements from a sequence. 127 128 *elements* is a sequence with zero or more elements. 129 130 """ 131 for element in elements: 132 self._assert_is_element(element) 133 self._children.extend(elements) 134 135 def insert(self, index, subelement): 136 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 137 """Insert *subelement* at position *index*.""" 138 self._assert_is_element(subelement) 139 self._children.insert(index, subelement) 140 141 def _assert_is_element(self, e): 142 # Need to refer to the actual Python implementation, not the 143 # shadowing C implementation. 144 if not isinstance(e, _Element_Py): 145 raise TypeError(\'expected an Element, not %s\' % type(e).__name__) 146 147 def remove(self, subelement): 148 在当前节点在子节点中删除某个节点 149 """Remove matching subelement. 150 151 Unlike the find methods, this method compares elements based on 152 identity, NOT ON tag value or contents. To remove subelements by 153 other means, the easiest way is to use a list comprehension to 154 select what elements to keep, and then use slice assignment to update 155 the parent element. 156 157 ValueError is raised if a matching element could not be found. 158 159 """ 160 # assert iselement(element) 161 self._children.remove(subelement) 162 163 def getchildren(self): 164 获取所有的子节点（废弃） 165 """(Deprecated) Return all subelements. 166 167 Elements are returned in document order. 168 169 """ 170 warnings.warn( 171 "This method will be removed in future versions. " 172 "Use \'list(elem)\' or iteration over elem instead.", 173 DeprecationWarning, stacklevel=2 174 ) 175 return self._children 176 177 def find(self, path, namespaces=None): 178 获取第一个寻找到的子节点 179 """Find first matching element by tag name or path. 180 181 *path* is a string having either an element tag or an XPath, 182 *namespaces* is an optional mapping from namespace prefix to full name. 183 184 Return the first matching element, or None if no element was found. 185 186 """ 187 return ElementPath.find(self, path, namespaces) 188 189 def findtext(self, path, default=None, namespaces=None): 190 获取第一个寻找到的子节点的内容 191 """Find text for first matching element by tag name or path. 192 193 *path* is a string having either an element tag or an XPath, 194 *default* is the value to return if the element was not found, 195 *namespaces* is an optional mapping from namespace prefix to full name. 196 197 Return text content of first matching element, or default value if 198 none was found. Note that if an element is found having no text 199 content, the empty string is returned. 200 201 """ 202 return ElementPath.findtext(self, path, default, namespaces) 203 204 def findall(self, path, namespaces=None): 205 获取所有的子节点 206 """Find all matching subelements by tag name or path. 207 208 *path* is a string having either an element tag or an XPath, 209 *namespaces* is an optional mapping from namespace prefix to full name. 210 211 Returns list containing all matching elements in document order. 212 213 """ 214 return ElementPath.findall(self, path, namespaces) 215 216 def iterfind(self, path, namespaces=None): 217 获取所有指定的节点，并创建一个迭代器（可以被for循环） 218 """Find all matching subelements by tag name or path. 219 220 *path* is a string having either an element tag or an XPath, 221 *namespaces* is an optional mapping from namespace prefix to full name. 222 223 Return an iterable yielding all matching elements in document order. 224 225 """ 226 return ElementPath.iterfind(self, path, namespaces) 227 228 def clear(self): 229 清空节点 230 """Reset element. 231 232 This function removes all subelements, clears all attributes, and sets 233 the text and tail attributes to None. 234 235 """ 236 self.attrib.clear() 237 self._children = [] 238 self.text = self.tail = None 239 240 def get(self, key, default=None): 241 获取当前节点的属性值 242 """Get element attribute. 243 244 Equivalent to attrib.get, but some implementations may handle this a 245 bit more efficiently. *key* is what attribute to look for, and 246 *default* is what to return if the attribute was not found. 247 248 Returns a string containing the attribute value, or the default if 249 attribute was not found. 250 251 """ 252 return self.attrib.get(key, default) 253 254 def set(self, key, value): 255 为当前节点设置属性值 256 """Set element attribute. 257 258 Equivalent to attrib[key] = value, but some implementations may handle 259 this a bit more efficiently. *key* is what attribute to set, and 260 *value* is the attribute value to set it to. 261 262 """ 263 self.attrib[key] = value 264 265 def keys(self): 266 获取当前节点的所有属性的 key 267 268 """Get list of attribute names. 269 270 Names are returned in an arbitrary order, just like an ordinary 271 Python dict. Equivalent to attrib.keys() 272 273 """ 274 return self.attrib.keys() 275 276 def items(self): 277 获取当前节点的所有属性值，每个属性都是一个键值对 278 """Get element attributes as a sequence. 279 280 The attributes are returned in arbitrary order. Equivalent to 281 attrib.items(). 282 283 Return a list of (name, value) tuples. 284 285 """ 286 return self.attrib.items() 287 288 def ite以上是关于模块补充的主要内容，如果未能解决你的问题，请参考以下文章
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