Files
python3-cookbook/cookbook/c01/p08_calculate_dict.py
2014-09-02 10:52:13 +08:00

45 lines
1.2 KiB
Python

#!/usr/bin/env python
# -*- encoding: utf-8 -*-
"""
Topic: 字典的数据运算
Desc :
"""
def calc_dict():
prices = {
'ACME': 45.23,
'AAPL': 612.78,
'IBM': 205.55,
'HPQ': 37.20,
'FB': 10.75
}
min_price = min(zip(prices.values(), prices.keys()))
# min_price is (10.75, 'FB')
max_price = max(zip(prices.values(), prices.keys()))
# max_price is (612.78, 'AAPL')
prices_sorted = sorted(zip(prices.values(), prices.keys()))
# prices_sorted is [(10.75, 'FB'), (37.2, 'HPQ'),
# (45.23, 'ACME'), (205.55, 'IBM'),
# (612.78, 'AAPL')]
prices_and_names = zip(prices.values(), prices.keys())
print(min(prices_and_names)) # OK
print(max(prices_and_names)) # ValueError: max() arg is an empty sequence
min(prices) # Returns 'AAPL'
max(prices) # Returns 'IBM'
min(prices, key=lambda k: prices[k]) # Returns 'FB'
max(prices, key=lambda k: prices[k]) # Returns 'AAPL'
min_value = prices[min(prices, key=lambda k: prices[k])]
prices = { 'AAA' : 45.23, 'ZZZ': 45.23 }
min(zip(prices.values(), prices.keys()))
# (45.23, 'AAA')
max(zip(prices.values(), prices.keys()))
# (45.23, 'ZZZ')