如何在两个级别的循环中检查按键？

Question

我有看起来像这样的数据：

{
    'METTS MARK': {
        'salary': 365788,
        'to_messages': 807,
        'deferral_payments': 'NaN',
        'total_payments': 1061827,
        'exercised_stock_options': 'NaN',
        'bonus': 600000,
        'restricted_stock': 585062,
        'shared_receipt_with_poi': 702,
        'restricted_stock_deferred': 'NaN',
        'total_stock_value': 585062,
        'expenses': 94299,
        'loan_advances': 'NaN',
        'from_messages': 29,
        'other': 1740,
        'from_this_person_to_poi': 1,
        'poi': False,
        'director_fees': 'NaN',
        'deferred_income': 'NaN',
        'long_term_incentive': 'NaN',
        'email_address': 'mark.metts@enron.com',
        'from_poi_to_this_person': 38
    },
    'BAXTER JOHN C': {
        'salary': 267102,
        'to_messages': 'NaN',
        'deferral_payments': 1295738,
        'total_payments': 5634343,
        'exercised_stock_options': 6680544,
        'bonus': 1200000,
        'restricted_stock': 3942714,
        'shared_receipt_with_poi': 'NaN',
        'restricted_stock_deferred': 'NaN',
        'total_stock_value': 10623258,
        'expenses': 11200,
        'loan_advances': 'NaN',
        'from_messages': 'NaN',
        'other': 2660303,
        'from_this_person_to_poi': 'NaN',
        'poi': False,
        'director_fees': 'NaN',
        'deferred_income': -1386055,
        'long_term_incentive': 1586055,
        'email_address': 'NaN',
        'from_poi_to_this_person': 'NaN'
    },
    'ELLIOTT STEVEN': {
        'salary': 170941,
        'to_messages': 'NaN',
        'deferral_payments': 'NaN',
        'total_payments': 211725,
        'exercised_stock_options': 4890344,
        'bonus': 350000,
        'restricted_stock': 1788391,
        'shared_receipt_with_poi': 'NaN',
        'restricted_stock_deferred': 'NaN',
        'total_stock_value': 6678735,
        'expenses': 78552,
        'loan_advances': 'NaN',
        'from_messages': 'NaN',
        'other': 12961,
        'from_this_person_to_poi': 'NaN',
        'poi': False,
        'director_fees': 'NaN',
        'deferred_income': -400729,
        'long_term_incentive': 'NaN',
        'email_address': 'steven.elliott@enron.com',
        'from_poi_to_this_person': 'NaN'
    },
    'CORDES WILLIAM R': {
        'salary': 'NaN',
        'to_messages': 764,
        'deferral_payments': 'NaN',
        'total_payments': 'NaN',
        'exercised_stock_options': 651850,
        'bonus': 'NaN',
        'restricted_stock': 386335,
        'shared_receipt_with_poi': 58,
        'restricted_stock_deferred': 'NaN',
        'total_stock_value': 1038185,
        'expenses': 'NaN',
        'loan_advances': 'NaN',
        'from_messages': 12,
        'other': 'NaN',
        'from_this_person_to_poi': 0,
        'poi': False,
        'director_fees': 'NaN',
        'deferred_income': 'NaN',
        'long_term_incentive': 'NaN',
        'email_address': 'bill.cordes@enron.com',
        'from_poi_to_this_person': 10
    },
    'HANNON KEVIN P': {
        'salary': 243293,
        'to_messages': 1045,
        'deferral_payments': 'NaN',
        'total_payments': 288682,
        'exercised_stock_options': 5538001,
        'bonus': 1500000,
        'restricted_stock': 853064,
        'shared_receipt_with_poi': 1035,
        'restricted_stock_deferred': 'NaN',
        'total_stock_value': 6391065,
        'expenses': 34039,
        'loan_advances': 'NaN',
        'from_messages': 32,
        'other': 11350,
        'from_this_person_to_poi': 21,
        'poi': True,
        'director_fees': 'NaN',
        'deferred_income': -3117011,
        'long_term_incentive': 1617011,
        'email_address': 'kevin.hannon@enron.com',
        'from_poi_to_this_person': 32
    },
    ...........
}

以上就是我的数据。 我想计算这个数据集中有多少个poi是“ True”。

请帮我。

Answer 1

假设您将数据保存在名为data的字典中，则可以编写以下使用列表推导的代码：

print len([key for key in data if data[key]['poi']])

显示'poi'属性设置为True 。

Answer 2

普通迭代和增加计数器方法：

1. 使用for循环和items()方法迭代给定字典中的每个项目。
2. 检查poi键是否存在。
3. 如果poi具有True值，则增加true计数器。
4. 否则增加假计数器
5. 显示结果。

演示：

ppl_info = {'METTS MARK': {'salary': 365788, 'to_messages': 807, 'deferral_payments': 'NaN', 'total_payments': 1061827, 'exercised_stock_options': 'NaN', 'bonus': 600000, 'restricted_stock': 585062, 'shared_receipt_with_poi': 702, 'restricted_stock_deferred': 'NaN', 'total_stock_value': 585062, 'expenses': 94299, 'loan_advances': 'NaN', 'from_messages': 29, 'other': 1740, 'from_this_person_to_poi': 1, 'poi': False, 'director_fees': 'NaN', 'deferred_income': 'NaN', 'long_term_incentive': 'NaN', 'email_address': 'mark.metts@enron.com', 'from_poi_to_this_person': 38}, 
'BAXTER JOHN C': {'salary': 267102, 'to_messages': 'NaN', 'deferral_payments': 1295738, 'total_payments': 5634343, 'exercised_stock_options': 6680544, 'bonus': 1200000, 'restricted_stock': 3942714, 'shared_receipt_with_poi': 'NaN', 'restricted_stock_deferred': 'NaN', 'total_stock_value': 10623258, 'expenses': 11200, 'loan_advances': 'NaN', 'from_messages': 'NaN', 'other': 2660303, 'from_this_person_to_poi': 'NaN', 'poi': False, 'director_fees': 'NaN', 'deferred_income': -1386055, 'long_term_incentive': 1586055, 'email_address': 'NaN', 'from_poi_to_this_person': 'NaN'}, 
'ELLIOTT STEVEN': {'salary': 170941, 'to_messages': 'NaN', 'deferral_payments': 'NaN', 'total_payments': 211725, 'exercised_stock_options': 4890344, 'bonus': 350000, 'restricted_stock': 1788391, 'shared_receipt_with_poi': 'NaN', 'restricted_stock_deferred': 'NaN', 'total_stock_value': 6678735, 'expenses': 78552, 'loan_advances': 'NaN', 'from_messages': 'NaN', 'other': 12961, 'from_this_person_to_poi': 'NaN', 'poi': False, 'director_fees': 'NaN', 'deferred_income': -400729, 'long_term_incentive': 'NaN', 'email_address': 'steven.elliott@enron.com', 'from_poi_to_this_person': 'NaN'}, 
'CORDES WILLIAM R': {'salary': 'NaN', 'to_messages': 764, 'deferral_payments': 'NaN', 'total_payments': 'NaN', 'exercised_stock_options': 651850, 'bonus': 'NaN', 'restricted_stock': 386335, 'shared_receipt_with_poi': 58, 'restricted_stock_deferred': 'NaN', 'total_stock_value': 1038185, 'expenses': 'NaN', 'loan_advances': 'NaN', 'from_messages': 12, 'other': 'NaN', 'from_this_person_to_poi': 0, 'poi': False, 'director_fees': 'NaN', 'deferred_income': 'NaN', 'long_term_incentive': 'NaN', 'email_address': 'bill.cordes@enron.com', 'from_poi_to_this_person': 10}, 
'HANNON KEVIN P': {'salary': 243293, 'to_messages': 1045, 'deferral_payments': 'NaN', 'total_payments': 288682, 'exercised_stock_options': 5538001, 'bonus': 1500000, 'restricted_stock': 853064, 'shared_receipt_with_poi': 1035, 'restricted_stock_deferred': 'NaN', 'total_stock_value': 6391065, 'expenses': 34039, 'loan_advances': 'NaN', 'from_messages': 32, 'other': 11350, 'from_this_person_to_poi': 21, 'poi': True, 'director_fees': 'NaN', 'deferred_income': -3117011, 'long_term_incentive': 1617011, 'email_address': 'kevin.hannon@enron.com', 'from_poi_to_this_person': 32}
}

poi_true = 0
poi_false = 0

for section, info in  ppl_info.items():
    if "poi" in info:
        if info["poi"]:
            poi_true += 1
        else:
            poi_false += 1

print "Result:\n POI True:%d\n POI False:%d "%(poi_true, poi_false)

输出：

$ python task4.py 
Result:
 POI True:1
 POI False:4

---

按收款柜台

演示：

import collections

result = collections.Counter()

for section, info in  ppl_info.items():
    if "poi" in info:
        result[info["poi"]] += 1 

print "Result:\n Dictinary: %s \n True:%d\n POI False:%d "%(result, result[True], result[False])

输出：

$ python task4.py 
Result:
 Dictinary: Counter({False: 4, True: 1}) 
 True:1
 POI False:4 

Answer 3

您可以对数据使用普通循环：

count_poi = 0
for v in somedict.itervalues():
    try:  # Only necessary if unsure about whether 'poi' is always a key
        if v['poi'] is True:
            count_poi += 1
    except KeyError:
        continue

请注意，如果您知道数据格式正确，则不需要try / except。

在这种情况下，您还可以使用sorter语法：

print len([v for v in data.itervalues() if v['poi'] is True])