Computer Science

the process of applying an algorithm to plaintext to produce ciphertext that cannot be understood (without decryption)

when a key (the attribute identifier) is paired with the data

an algorithm used to convert plaintext messages to ciphertext (encryption) or ciphertext to plaintext (decryption)

Dictionary challenge

This unit introduces pupils to the new data structures of records and dictionaries. They will develop a Caesar cipher encryption program using a dictionary as a cipher wheel. Pupils will explore how data can be read from and written to files and how this data can be used within a program.

Programming: dictionaries and data files

What type of data structure is used to store key-value pairs in Python?

a data structure that uses data pairings which are located with a key

used to identify each attribute held in a dictionary

A Caesar cipher with key +2 will change A to ...

What will be the output of this code?
```caesar = {"Y": "A", "Z": "B", "A": "C"}  
print(caesar["Z"])```

To add a new key-value pair to a dictionary, you can use the {{ }} operator.

What does this line return?
```chr(66)```

In a Python dictionary, each item is made up of a {{ }} and a value.

`{"apple": "fruit", "carrot": "vegetable"}`

`("apple": "fruit", "carrot": "vegetable")`

Which of these is a valid Python dictionary?

What will this code output? 
```my_dict = {"a": 1, "b": 2}
print(my_dict["b"])```

What will this code do?
```my_dict = {"cat": "meow", "dog": "bark"}
my_dict["dog"] = "woof"```

Starter Quiz