我会尽力解释这个问题，所以请为长篇文章道歉。
首先，我在这里有一个API（http://dev.c0l.in:5984/income_statements/_all_docs），在这本词典中还有5000个其他词典，我可以通过他们的ID访问（http://dev.c0l.in:5984/income_statements/30e901a7b7d8e98328dcd77c369b6ad7）
到目前为止，我已经创建了一个程序，可以对这些词典进行排序，并且只打印（到csv）与用户输入部门相关的词典（例如医疗保健）
但是，我希望能够实现过滤搜索，以便程序只打印高于或低于用户输入值的语句，例如仅检索来自（用户输入）期末股票的数据，并且仅检索低于（＆lt; =）期末股票的公司 - 40,000。
我的问题是，我不一定确定如何。
我理解如何获取用户输入，以及如何在字典中访问字典，但我不知道如何过滤或低于用户输入值。
这是我的代码的副本，任何指针都将不胜感激！
import urllib #Imports the url - library module (older the urllib2 but has some useful decodes if needed)
import urllib2 #Imports the Url- Library module (Most recently updated + used)
import csv #Imports the commands that allows for csv writing/reading
import json #Imports the ability to read/use Json data
import time #Imports the time module - allows the developer to examine benchmarks (How long did it take to fetch data)
import os
income_csv = csv.writer(open("Income Statement_ext.csv", "wb")) #This creates a CSV file and writes functions to it
financial_csv = csv.writer(open("Statement of financial position_ext.csv", "wb"))
#The two csv 'writers' create the headers for the information within the CSV file before the information from the api is added to it
financial_csv.writerow([
('Company name'),
('Non Current Assets'),
('Current Assets'),
('Equity'),
('Non-Current Assets'),
('Current Liabilities')])
income_csv.writerow([
('Company name'),
('Sales'),
('Opening Stock'),
('Purchases'),
('Closing Stock'),
('Expenses'),
('Interest payable'),
('Interest receivable')])
income_url = "http://dev.c0l.in:5984/income_statements/_all_docs"
income_request = urllib2.urlopen(income_url).read()
income_response = json.loads(income_request)
#defines the income url
financial_url = "http://dev.c0l.in:5984/financial_positions/_all_docs"
financial_request = urllib2.urlopen(financial_url).read()
financial_response = json.loads(financial_request)
#defines the financial postion url
count = 0
#sets the count for documents printed to 0
def income_statement_fn():
global count #allows for the count to be kept globally
print ("(Type help if you would like to see the available choices)")
income_user_input = raw_input("Which sector would you like to iterate through in Income Statement?: ").lower()# Asks the user which sector within the chosen statement he/she would like to examine
if income_user_input == "help":
print ("Available sectors are: ")
print ("Technology")
print ("Healthcare")
print ("Industrial goods")
print ("Financial")
print ("Utilities")
print ("Basic materials")
print ("Services")
income_statement_fn()
elif income_user_input == "technology" or income_user_input == "healthcare" or income_user_input == "industrial goods" or income_user_input == "financial" or income_user_input == "utilities" or income_user_input == "basic materials" or income_user_input == "services":
print 'Starting...' # I use this print to set a milestone (if it prints this, everything before it has worked without error)
start = time.clock()
start
for item in income_response['rows']:
is_url = "http://dev.c0l.in:5984/income_statements/" + item['id'] #This combines the api with the array's ID's allowing us to access every document automatically
is_request = urllib2.urlopen(is_url).read() #Opens is_url and reads the data
is_response = json.loads(is_request) #loads the data in json format
if is_response.get ('sector') == income_user_input: #matches the sector the user inputed - allows us to access that dictionary
income_csv.writerow([
is_response['company']['name'],
is_response['company']['sales'],
is_response['company']['opening_stock'],
is_response['company']['purchases'],
is_response['company']['closing_stock'],
is_response['company']['expenses'],
is_response['company']['interest_payable'],
is_response['company']['interest_receivable']]) # The lines of code above write the chosen fields to the csv file
count +=1
print ("filtering statements") + ("( "+" %s "+" )") % count
start
print start
restart_fn()
else:
print ("Invalid input!")
income_statement_fn()
def financial_statement_fn(): # Within this function is the code required to fetch information related to the financial position statement
global count # Allows for the count to be kept globally (outside the function)
print ("(Type help if you would like to see the available choices)")
financial_user_input = raw_input("Which sector would you like to iterate through in financial statements?: ").lower()
if financial_user_input == "help":
print ("Available sectors are: ")
print ("Technology")
print ("Healthcare")
print ("Industrial goods")
print ("Financial")
print ("Utilities")
print ("Basic materials")
print ("Services")
financial_statement_fn()
elif financial_user_input == "technology" or financial_user_input == "healthcare" or financial_user_input == "industrial goods" or financial_user_input == "financial" or financial_user_input == "utilities" or financial_user_input == "basic materials" or financial_user_input == "services":
print 'Starting'
for item in financial_response['rows']:
fs_url = "http://dev.c0l.in:5984/financial_positions/" + item['id']#This combines the api with the array's ID's allowing us to access every document automatically
fs_request = urllib2.urlopen(fs_url).read()
fs_response = json.loads(fs_request)
if fs_response.get ('sector') == financial_user_input:
financial_csv.writerow([
fs_response['company']['name'],
fs_response['company']['non_current_assets'],
fs_response['company']['current_assets'],
fs_response['company']['equity'],
fs_response['company']['non_current_liabilities'],
fs_response['company']['current_liabilities']])
count +=1
print ("printing statements") + ("( "+" %s "+" )") % count
print ("---------------------------------------------------------------------")
print ("finished fetching data")
print ("---------------------------------------------------------------------")
restart_fn()
else:
print ("Invalid Input!")
financial_statement_fn()
def launch_fn():
print ("Please type 'help' if you would like to examine all available options")
launch_user_input = raw_input("Welcome, Which statement would you like to examine?: ").lower()
if launch_user_input == "income" or launch_user_input == "income statement":
income_statement_fn()
elif launch_user_input == "financial" or launch_user_input == "financial statement":
financial_statement_fn()
elif launch_user_input == "help" :
print ("You can use the following commands on this menu: ")
print ("---------------------------------------------------------------------")
print ("Income or Income statement")
print ("Will allow you to retrieve data relating to financial Income statements")
print ("---------------------------------------------------------------------")
print ("Financial or Financial statement")
print ("Will allow you to retrieve data relating to the statement of financial position")
print ("---------------------------------------------------------------------")
launch_fn()
else:
print ("If you would like to look at the available options please type help")
launch_fn()
def restart_fn():
restart_prompt = raw_input("Would you like to examine another statement?: ").lower()
if restart_prompt == 'y' or restart_prompt == 'yes':
launch_fn()
count = 0
elif restart_prompt == 'n' or restart_prompt == 'no':
raise SystemExit("Shutting down....")
def restart_api_down_fn():
print ("Type 'y' or 'yes' to continue, 'n' or 'no' to exit or 'r' or 'reconnect' to test servers again")
restart_prompt_api = raw_input("Would you like to continue anyway?: ").lower()
if restart_prompt_api == 'r' or restart_prompt_api == 'reconnect' or restart_prompt_api == 'test':
api_status_fn()
count = 0
elif restart_prompt_api == 'n' or restart_prompt_api == 'no':
raise SystemExit("Shutting down....")
elif restart_prompt_api == 'y' or restart_prompt_api == 'yes':
print (" Continuing... Programme performance may be severely affected")
launch_fn()
else:
print ("Invalid input...")
restart_api_down_fn()
def api_status_fn():
hostname_income = "http://dev.c0l.in:5984/income_statements"
response_income = os.system("ping -c 1 " + hostname_income)
hostname_financial = "http://dev.c0l.in:5984/financial_positions"
response_financial = os.system("ping -c 1 " + hostname_financial)
global count
count = 0
if response_income == 0:
print hostname_income, 'is up!'
count +=1
else:
print hostname_income, 'is experiencing connection issues!'
if response_financial == 0:
print hostname_financial, 'is up!'
count +=1
else:
print hostname_financial, 'is experiencing connection issues!'
if count == 2:
launch_fn()
elif count == 0:
restart_api_down_fn() # Code only for UNIX SYSTEMS?
#def api_status_fn():
# hostname = "http://dev.c0l.in:5984/income_statements"
# ping = urllib.urlopen(hostname).getcode()
# if ping == "200":
# print 'oh no!'
# add filtering & sorting
api_status_fn()
如果您需要任何其他说明，请与我们联系。
干杯！
答案 0 :(得分：3)
我会说你的代码很混乱，如果你试图把它分解一下，你可能会有更多的运气。我将尝试在这个答案结束时提出一些建议。
从根本上说，您需要过滤所获得的特定结果。查看代码，我可以看到以下内容：
elif financial_user_input == "technology" or financial_user_input == "healthcare" or financial_user_input == "industrial goods" or financial_user_input == "financial" or financial_user_input == "utilities" or financial_user_input == "basic materials" or financial_user_input == "services":
print 'Starting'
for item in financial_response['rows']:
fs_url = "http://dev.c0l.in:5984/financial_positions/" + item['id']#This combines the api with the array's ID's allowing us to access every document automatically
fs_request = urllib2.urlopen(fs_url).read()
fs_response = json.loads(fs_request)
if fs_response.get ('sector') == financial_user_input:
此代码混合了以下职责：
如果您将这些职责分解为单独的方法，那么您会发现您的代码更容易推理。此外，正如我将很快展示的那样，以这种方式拆分可以让您重新组合不同的部分，以自定义过滤记录的方式等。
如果它分开了一点：
def _get_single_record(id):
""" Request an individual financial position.
This does not filter """
... read and return the json decoded data ...
def _record_matches_sector(record, sector):
""" Determine if the record provided matches the sector """
return record['sector'] == sector
def _record_meets_closing_stock_limit(record, limit):
""" Determine if the record provided has a
closing stock of at least limit """
return record['closing stock'] >= limit
def _get_all_filtered_records(ids, sector, limit):
""" Return all financial position records that
match the sector and closing stock limit """
record_generator = (_get_single_record(id) for id in ids)
return (
record for record in record_generator
if _record_matches_sector(record, sector)
and _record_meets_closing_stock_limit(record, limit)
)
这显然只返回一个生成器，它返回与您的扇区和限制匹配的记录。您可以添加更多测试等，但更新代码以测试每个测试仍然非常手动。您需要的是一种将一些可选测试应用于record_generator并返回匹配结果的方法。
这在python中非常简单，因为python将函数视为第一类对象（意味着可以将它们分配给变量），并且可以使用lambdas快速创建自定义函数。这意味着您可以将_get_all_filtered_records重新声明为：
def _make_limit_test(limit):
""" This returns a function which accepts records that meet the limit """
return lambda record: record['closing stock'] >= limit
def _make_sector_test(sector):
""" This returns a function which accepts records that match the sector """
return lambda record: record['sector'] == sector
def _filter_records_by_tests(ids, tests):
""" Returns all the records that pass all the tests """
record_generator = (_get_single_financial_position_record(id) for id in ids)
for record in record_generator:
if all(test(record) for test in tests):
yield record
然后，您可以通过询问用户来构建要传递的测试列表。这将是一个足够的演示，只是为了验证这种方法是否有效：
def demo_filtering_by_healthcare_and_40k(ids):
tests = [_make_sector_test("healthcare"), _make_limit_test(40000)]
return _filter_records_by_tests(ids, tests)
正如您所看到的，我的方法名称很长，而且方法很短。这实际上是个人风格的问题，但我发现以这种方式这样做可以明确表示方法的作用，并允许您快速理解代码以验证它与名称匹配。
因此，为了解决这个问题，您要从远程api请求记录。您可以使用列表推导来过滤这些。列表推导非常强大，允许您获取源数据并对其进行转换并对其进行过滤。阅读它们会对你有所帮助。