Dictionaries – Methods (keys, values, items, get)
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. What does .keys() return?
2. What does .values() return?
3. What does .items() return?
4. d.get('x', 0) what happens if 'x' doesn't exist?
5. d.get('x') what if 'x' doesn't exist and no default?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1d = {'a': 1} d.get('b') print(d['b']) | AOk: Loop over key-value pairs | |
| 2d = {'x': 5} d.pop('y') | BError: Key 'y' not in dict | |
| 3d.get('missing', 0) | CValid: Returns 0 if key absent | |
| 4for k, v in d.items(): print(k, v) | DError: .get() doesn't add the key | |
| 5d = {'a':1,'b':2} print(list(d.keys())) | EOutput: 99 | |
| 6d = {'a':1} print(d.get('b', 99)) | FOutput: ['a', 'b'] |
C
Definitions
.keys()
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
d = {'a': 1, 'b': 2}
print(d.____( ))
2.
d = {'a': 1, 'b': 2}
print(d.______( ))
3.
d = {'a': 1}
print(d.___('b', 0))
4.
d = {'x': 10}
val = d.___('x')
5.
d = {'a': 1}
d.______({'b': 2})
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
d = {'a': 1, 'b': 2}
B
all_keys = d.key()
C
print('Keys:', all_keys)
D
print('Done')
Question 2
A
d = {'a': 1, 'b': 2}
B
all_vals = d.value()
C
print('Values:', all_vals)
D
print('Done')
Question 3
A
d = {'a': 1, 'b': 2}
B
all_items = d.item()
C
print('Items:', all_items)
D
print('Done')
Question 4
A
d = {'a': 1, 'b': 2}
B
val = d.get['b']
C
print('Value:', val)
D
print('Done')
Question 5
A
result = {'a': 1, 'b': 2}.pop()
B
label = 'Dict'
C
print('Result:', result)
D
print('Done')
Answer Key
Dictionaries – Methods (keys, values, items, get)
Section A: Quick Questions
Q1
A — All the keys
Q2
A — All the values
Q3
A — Key-value pairs as tuples
Q4
B — Returns 0 (the default)
Q5
B — Returns None
Section B: Match the Pairs
Q1
d = {'a': 1}
d.get('b')
print(d['b']) → Error: .get() doesn't add the key
Q2
d = {'x': 5}
d.pop('y') → Error: Key 'y' not in dict
Q3
d.get('missing', 0) → Valid: Returns 0 if key absent
Q4
for k, v in d.items():
print(k, v) → Ok: Loop over key-value pairs
Q5
d = {'a':1,'b':2}
print(list(d.keys())) → Output: ['a', 'b']
Q6
d = {'a':1}
print(d.get('b', 99)) → Output: 99
Section C: Definitions
Q1
.keys() — Returns all keys in the dictionary.~~.values()Section D: Fill in the Blanks
Q1
d = {'a': 1, 'b': 2}
print(d.keys( ))Q2
d = {'a': 1, 'b': 2}
print(d.values( ))Q3
d = {'a': 1}
print(d.get('b', 0))Q4
d = {'x': 10}
val = d.pop('x')Q5
d = {'a': 1}
d.update({'b': 2})Section E: Spot the Error
Q1
B — It's keys() with an 's': not key()
Q2
B — It's values() with an 's': not value()
Q3
B — It's items() with an 's': not item()
Q4
B — Use parentheses () to call methods, not square brackets []
Q5
A — dict.pop() requires a key argument: which key to remove?