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数据：

实例：

import requestspayload = {    'projectBean.startDate' : '2017-06-18',    'projectBean.endDate' : '2017-09-18',    'queryYN' : 'true'}response = requests.post('http://www.safe.gov.cn/AppStructured/view/project_RMBQuery.action',                        data=payload)html = response.text

import sqlite3 as dbwith db.connect('currency.sqlite') as con:    df_rates.to_sql('currency_data', con=con, if_exists='replace', index=None)

from datetime import datetime, timedeltacurrent_time = datetime.now()for i in range(0, 300, 31):    # 为了避免重复，range T - days T = 1    start_date = (current_time - timedelta(days = i + 30)).strftime('%Y-%m-%d')    end_date = (current_time - timedelta(days = i)).strftime('%Y-%m-%d')

def get_currency(start, end):    payload = {    'projectBean.startDate' : start,    'projectBean.endDate' : end,    'queryYN' : 'true'    }    response = requests.post('http://www.safe.gov.cn/AppStructured/view/project_RMBQuery.action',                            data=payload)    html = response.text    doc = pq(html)    info = '
   
    {info}
'.format(info=doc('#InfoTable').html())    dfs = pd.read_html(info, header=0)    df_rates = pd.melt(dfs[0], col_level=0, id_vars='日期')    df_rates.columns = ['date', 'currency', 'exchange']    with db.connect('currency.sqlite') as con:        df_rates.to_sql('currency_data', con=con, if_exists='append', index=None)        current_time = datetime.now()for i in range(0, 300, 31):    # 为了避免重复，range T - days T = 1    start_date = (current_time - timedelta(days = i + 30)).strftime('%Y-%m-%d')    end_date = (current_time - timedelta(days = i)).strftime('%Y-%m-%d')    print(i, start_date, end_date)    get_currency(start_date, end_date)

with db.connect('currency.sqlite') as con:    df = pd.read_sql('select * from currency_data where currency = "美元"', con=con)

% pylab  inlinedf.plot(kind='line', rot=30)

with db.connect('currency.sqlite') as con:    df = pd.read_sql('select * from currency_data where currency in ("美元", "英镑")', con=con)        df['date'] = pd.to_datetime(df['date'] ,format='%Y-%m-%d')df.info()