string(字符串) hash(哈希) list(列表) set(集合) zset(sorted set:有序集合) 1.String 字符串数据类型 String 是最常用的一种数据类型,普通的 key/value 存储都可以归为此类,即可以完全实现目前 Memcached 的功能,并且效率更高。 还可以享受 Redis 的定时持久化,操作日志及
create_table_sql =f"CREATE TABLE IF NOT EXISTS{table_name}({', '.join(set(columns))})"cursor.execute(create_table_sql)print('数据表创建成功') cursor.close() self.disconnect_from_database()deftable_exists(self, table_name):"""检查数据表是否存在"""self.connect_to_database() cursor =...
defset(self,key,value):"""Sets the key to the value, replacing any existing value."""bucket,slot=self.get_slot(key)ifslot:# the key exists,replace it slot.value=(key,value)else:# the key does not,append to create it bucket.push((key,value))defdelete(self,key):"""Deletes the g...
myarr)) # 字典 print(mydict) # 构造方法 ser1 = pd.Series(mylist) ser2 = pd.Series(myarr) ser3 = pd.Series(mydict) print(ser3.head()) # 取 ser3 的前五行 print(ser3.head(1)) # 取 ser3 的第一行 print(ser1,
用户在创建好数据仓库集群后使用PyGreSQL第三方库连接到集群,则可以使用Python访问GaussDB(DWS),并进行数据表的各类操作。GaussDB(DWS)集群已绑定弹性IP。已获取GaussDB(DWS)集群的数据库管理员用户名和密码。请注意,由于MD5算法已经被证实存在碰撞可能,已严禁将之用于
set -> set() # only care about presense of the elements, constant time O(1) look up dict -> {} # constant time O(1) look up for hash maps tuple -> () # tuple is a like a list but you cannot change the values in a tuple once it's defined. Tuples are good for storing ...
WriteLine(infos_dict["name"]); // Console.WriteLine(infos_dict["mmd"]); //#查不到就异常 // 先看看有没有 ContainsKey(key),看值就 ContainsValue(value) if (infos_dict.ContainsKey("mmd")) Console.WriteLine(infos_dict["mmd"]); // len(infos_dict) #有几对key,value Console.WriteLine(...
robot.set_url("http://"+site+"/robots.txt") robot.read() # For each entry, look at the rule lines and add the path to paths if # disallowed for entry in robot.entries: for line in entry.rulelines: not line.allowance and paths.append(line.path) return set(paths) for ...
Python语言采用严格的缩进来表示程序逻辑。也就是我们所说的Python程序间的包含与层次关系。一般代码不要求缩进,顶行编写且不留空白。在if、while、for、def、class等保留字所在完整语句后通过英文的“:”结尾并在之后行进行缩进,表明后续代码与紧邻无缩进语句的所属关系。
>>> dictionary == ordered_dict # If a == b True >>> dictionary == another_ordered_dict # and b == c True >>> ordered_dict == another_ordered_dict # then why isn't c == a ?? False # We all know that a set consists of only unique elements, # let's try making a set ...