判断某个key是否在字典d中存在，以下做法正确且严谨的是：（）A、’key’ind.keys（）B、d.get（’key’）isnotNoneC、hasattr（d，’key’）D、’key’ind
判断某个key是否在字典d中存在，以下做法正确且严谨的是：（）
- A、’key’ind.keys（）
- B、d.get（’key’）isnotNone
- C、hasattr（d，’key’）
- D、’key’ind
相关考题：
Python中通过Key来从字典object中读取对应的Value的方法有() A.object[key]B.object.get(key)C.object.pop(key)D.object.pop()
In a public-key cryptosystem,(71)encrypted with the public key can only be deciphered with the private key from the same(72). Conversely,(71)encrypted with the private key can be decrypted only with the public key. Users can make their public keys(73)available or place them at a key distribution center or others to access. However, the private key must be(74)safe. In public-key systems there's no(75)to find a safe channel for communicating a shared secret key.A．binarytextB．hypertextC．plaintextD．supertext
Which statement is true regarding a session key in the Diffie－Hellman key－exchange process?() A. A session key value is exchanged across the network.B. A session key never passes across the network.C. A session key is used as the key for asymmetric data encryption.D. A session key is used as the key for symmetric data encryption.
键盘事件的执行顺序是（）。AKey Press、Key Down、Key UpBKey Down、Key Press、Key UpCKey Up、Key Down、Key PressDKey Up、Key Press、Key Down
加密算法是一种数学函数，如果用C表示加密后的密文，M是欲加密的明文，Key表示密钥，F表示加密算法，以下正确表示加密算法原理的数学式是（）。A、M=F（C，Key）B、C=F（M，Key）C、Key=F（C，M）D、F=（C，M，Key）
By default， what type of SSH server key is generated by Cisco NX-OS Software？（）A、 DSA key generated with 512 bitsB、 RSA key generated with 768 bitsC、 RSA key generated with 1024 bitsD、 DSA key generated with 1024 bitsE、 RSA key generated with 2048 bits
Which three are distinctions between asymmetric and symmetric algorithms？ （）A、Only symmetric algorithms have a key exchange technology built inB、Asymmetric algorithms are used quite often as key exchange protocols for symmetricalgorithmsC、Only asymmetric algorithms have a key exchange technology built inD、Asymmetric algorithms are based on more complex mathematical computations
PKI是（）。A、Private Key InfrastructureB、Public Key InstituteC、Public Key Infrastructure公钥基础设施D、Private Key Institute
键盘事件的执行顺序是（）。A、Key Press、Key Down、Key UpB、Key Down、Key Press、Key UpC、Key Up、Key Down、Key PressD、Key Up、Key Press、Key Down
假设d为一个空字典d={}。以下语句中执行后，d的内容将会变为{’key’：1}：（）A、d[’key’]=1B、d.update（’key’=1）C、d.setdefault（’key’，1）D、d.update（key=1）
下列关于localStorage的说法中不正确的是（）A、localStoragE.getItem（key）。该接口用于获取指定key本地存储的值B、localStoragE.length。该接口表示对象中存储的键值对的数量C、localStoragE.removeItem（key）。该接口用于删除指定key本地存储的值D、localStoragE.key（index）。该接口用于将value存储到key字段。index从0开始
以下能正确进行字符串赋值或赋初值的语句组是（）A、charstr[3]="key"；B、charstr[3]={’k’，’e’，’y’}；C、charstr[4]；str="key"；D、char*s；s="key"；
要在session对象中保存属性，可以使用以下哪个语句？（）A、session.getAttribute（“key”,”value”）B、session.setAttribute（“key”,”value”）C、session.setAtrribute（“key”）D、session.getAttribute（“key”）
public class Key { private long id1； private long 1d2； // class Key methods } A programmer is developing a class Key， that will be used as a key in a standard java.util.HashMap. Which two methods should be overridden to assure that Key works correctly as a key？（）A、 public int hashCode（）B、 public boolean equals（Key k）C、 public int compareTo（Object o）D、 public boolean equals（Object o）E、 public boolean compareTo（Key k）
Which two statements are true about the primary key constraint in a table？ （）A、It is not possible to disable the primary key constraint.B、It is possible to have more than one primary key constraint in a single table.C、The primary key constraint can be referred by only one foreign key constraint.D、The primary key constraint can be imposed by combining more than one column.E、The non-deferrable primary key constraint creates an unique index on the primary key column if it is not already indexed.
PKI的全称是（）。A、Private Key IntrusionB、Public Key IntrusionC、Private Key InfrastructureD、Public Key Infrastructure
PKI是（）。A、Private Key lnfrastructureB、Public Key lnstituteC、Public Key lnfrastructureD、Private Key lnstitute
单选题键盘事件的执行顺序是（）。AKey Press、Key Down、Key UpBKey Down、Key Press、Key UpCKey Up、Key Down、Key PressDKey Up、Key Press、Key Down
单选题PKI是（）。APrivate Key InfrastructureBPublic Key InstituteCPublic Key Infrastructure公钥基础设施DPrivate Key Institute
单选题Which statement is true regarding a session key in the Diffie-Hellman key-exchange process?（）AA session key value is exchanged across the network.BA session key never passes across the network.CA session key is used as the key for asymmetric data encryption.DA session key is used as the key for symmetric data encryption.
单选题By default， what type of SSH server key is generated by Cisco NX-OS Software？（）A DSA key generated with 512 bitsB RSA key generated with 768 bitsC RSA key generated with 1024 bitsD DSA key generated with 1024 bitsE RSA key generated with 2048 bits
多选题public class Key { private long id1； private long 1d2； // class Key methods } A programmer is developing a class Key， that will be used as a key in a standard java.util.HashMap. Which two methods should be overridden to assure that Key works correctly as a key？（）Apublic int hashCode（）Bpublic boolean equals（Key k）Cpublic int compareTo（Object o）Dpublic boolean equals（Object o）Epublic boolean compareTo（Key k）
单选题被FOREIGN KEY参照的列在表中应该具有（）ADEFAULT约束BCHECK约束CPRIMARY KEY约束DREIGN KEY约束