尝试从嵌套字典中打印百分比

Question

我有一个解决方法，但我创建了一个应该可以工作的简约代码，但事实并非如此。我说 "should" 是因为当我使用我除法的代码部分，乘以 100，并使用 "{0:.0f}% 和我的旧代码打印时，它起作用了。但是，我认为我尝试了一些过于概念化的东西

import csv, itertools
from math import floor
filename = 'denton_housing.csv'
denton_housing = {}

def create_nested_housing_dict():
    with open(filename, 'r', encoding='utf8', newline='') as f:
        for row in csv.DictReader(f, delimiter=','):
            try:
                denton_housing[row['year']][row['title_field']] = int(row['value'])
            except KeyError:
                denton_housing[row['year']] = {}
    return denton_housing

data = create_nested_housing_dict()


for key, value in data.items():
    print(key + '         ' + "{0:.0f}%".format(int(value['Vacant Housing Units'])) / \
        int(value['Total Housing Units']) * 100 + key + '         ' + \
        "{0:.0f}%".format(int(value['Occupied Housing Units'])) / \
        int(value['Total Housing Units']) * 100)

所有这些给我的是：

Traceback (most recent call last):
  File "Dictest.py", line 37, in <module>
    int(value['Total Housing Units']) * 100 + key + '         ' + \
KeyError: 'Total Housing Units'

这是我的 csv：

year,title_field,value
2014,Total Housing Units,49109
2014,Vacant Housing Units,2814
2014,Occupied Housing Units,46295
2013,Total Housing Units,47888
2013,Vacant Housing Units,4215
2013,Occupied Housing Units,43673
2012,Total Housing Units,45121
2012,Vacant Housing Units,3013
2012,Occupied Housing Units,42108
2011,Total Housing Units,44917
2011,Vacant Housing Units,4213
2011,Occupied Housing Units,40704
2010,Total Housing Units,44642
2010,Vacant Housing Units,3635
2010,Occupied Housing Units,41007
2009,Total Housing Units,39499
2009,Vacant Housing Units,3583
2009,Occupied Housing Units,35916
2008,Total Housing Units,41194
2008,Vacant Housing Units,4483
2008,Occupied Housing Units,36711

Answer 1

这应该有所帮助。密钥 'Total Housing Units' 未存储在您的 'denton_housing' 字典中。

演示

import csv, itertools
from math import floor
filename = 'denton_housing.csv'
denton_housing = {}

def create_nested_housing_dict():
    with open(filename, 'r', encoding='utf8', newline='') as f:
        for row in csv.DictReader(f, delimiter=','):
            if row['year'] not in denton_housing:   #UPDATE
                denton_housing[row['year']] = {}
            try:
                denton_housing[row['year']][row['title_field']] = int(row['value'])
            except KeyError:
                denton_housing[row['year']] = {}
    return denton_housing

data = create_nested_housing_dict()


for key, value in data.items():
    print(key + '         ' + "{0:.0f}%".format(int(value['Vacant Housing Units'])) / \
        int(value['Total Housing Units']) * 100 + key + '         ' + \
        "{0:.0f}%".format(int(value['Occupied Housing Units'])) / \
        int(value['Total Housing Units']) * 100)

Answer 2

检查 data 字典后，我发现：

Key: 2014
Value: {'Vacant Housing Units': 2814, 'Occupied Housing Units': 46295}
Key: 2008
Value: {'Vacant Housing Units': 4483, 'Occupied Housing Units': 36711}
Key: 2009
Value: {'Vacant Housing Units': 3583, 'Occupied Housing Units': 35916}
Key: 2011
Value: {'Vacant Housing Units': 4213, 'Occupied Housing Units': 40704}
Key: 2010
Value: {'Vacant Housing Units': 3635, 'Occupied Housing Units': 41007}
Key: 2013
Value: {'Vacant Housing Units': 4215, 'Occupied Housing Units': 43673}
Key: 2012
Value: {'Vacant Housing Units': 3013, 'Occupied Housing Units': 42108}

发生这种情况是因为“总住房单元数”是每年的第一行。
因此 try 块失败并且“Total Housing Units”未添加到字典中。
然而，对于“空置住房单元”和“已占用住房单元”，try 块工作顺利，数据被添加到字典中。

尝试从嵌套字典中打印百分比

Trying to print percentages from nested dictionaries

python

csv

dictionary

floor