keys values items

When working with dictionaries, it’s sometimes important to iterate over all the keys, or maybe all the values, or sometimes all the key-value pairs. Accessing all the keys is possible through the keys() method. Accessing all the values is possible through the values() method, while accessing the key-value pairs is possible through the items() method:

population = {
	'US': 3295000000,
	'Mexico': 129000000,
	'Armenia': 3000000,
	'Portugal': 10300000
}

for k in population.keys():
	print(k.lower())

# Or even
for k in population:
	print(k.lower())

# us
# mexico
# armenia
# portugal

for v in population.values():
	print(v * 2)

# 6590000000
# 258000000
# 6000000
# 20600000

# population.items() is a list of tuples
# each tuple is a (key, value) pair: ('US', 3295000000)
for k, v in population.items():
	print(f'{k.lower()}: {v * 2}')

# Alternatively
for k in population:
	print(f'{k.lower()}: {population[k] * 2}')

# us: 6590000000
# mexico: 258000000
# armenia: 6000000
# portugal: 20600000

Challenge

Given a list of n patients with their blood pressure measurements, you are asked to calculate the average blood pressure for each patient. There are m measurements, each of the form patient-name: blood-pressure.

The first line of the input contains a single integer m. The next m lines contain the measurements of the form patient-name: blood-pressure.

The program should print the average blood pressure per patient in the order of appearance in the input. The format should be similar to the input patient-name: average-blood-pressure.

Input	Output
6 Anna: 100 Ani: 120 Anna: 120 Anna: 90 Ani: 100 Bob: 90	Anna: 103.33333333333333 Ani: 110 Bob: 90

Challenge

Constraints

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