Phython: How to extract a number-CodePudding

i just started up using phython & i try to help my dad to develop a small program:

from a query i get a retun that i converted into a dict as i want to extract the 'last_price': '1704.50'. I tried it with find, count ... but it seems that i'm running into a wall.

here is the string & it looks like that the bracket makes it harder to extract:

dict_items([('ret_code', 0), ('ret_msg', 'OK'), ('ext_code', ''), ('ext_info', ''), ('result', [{'symbol': 'ETHUSDT', 'bid_price': '1701.8', 'ask_price': '1702', 'last_price': '1704.50', 'last_tick_direction': 'PlusTick', 'prev_price_24h': '1647.55', 'price_24h_pcnt': '0.034566', 'high_price_24h': '1710.55', 'low_price_24h': '1620.40', 'prev_price_1h': '1679.40', 'price_1h_pcnt': '0.014945', 'mark_price': '1702.51', 'index_price': '1702.38', 'open_interest': 150155.81, 'open_value': '0.00', 'total_turnover': '54418340521.33', 'turnover_24h': '63239638.53', 'total_volume': 58525803.73, 'volume_24h': 37976.79, 'funding_rate': '0.0001', 'predicted_funding_rate': '0.0001', 'next_funding_time': '2022-08-25T08:00:00Z', 'countdown_hour': 1, 'delivery_fee_rate': '', 'predicted_delivery_price': '', 'delivery_time': ''}]), ('time_now', '1661411154.330653')])

Any idea is more than welcome

Thanks Alice

CodePudding user response：

Hope I'm uderstanding it right but this works for me:

d=dict([('ret_code', 0), ('ret_msg', 'OK'), ('ext_code', ''), ('ext_info', ''), ('result', [{'symbol': 'ETHUSDT', 'bid_price': '1701.8', 'ask_price': '1702', 'last_price': '1704.50', 'last_tick_direction': 'PlusTick', 'prev_price_24h': '1647.55', 'price_24h_pcnt': '0.034566', 'high_price_24h': '1710.55', 'low_price_24h': '1620.40', 'prev_price_1h': '1679.40', 'price_1h_pcnt': '0.014945', 'mark_price': '1702.51', 'index_price': '1702.38', 'open_interest': 150155.81, 'open_value': '0.00', 'total_turnover': '54418340521.33', 'turnover_24h': '63239638.53', 'total_volume': 58525803.73, 'volume_24h': 37976.79, 'funding_rate': '0.0001', 'predicted_funding_rate': '0.0001', 'next_funding_time': '2022-08-25T08:00:00Z', 'countdown_hour': 1, 'delivery_fee_rate': '', 'predicted_delivery_price': '', 'delivery_time': ''}]), ('time_now', '1661411154.330653')])

d['result'][0]['last_price']

gives the number. Notice the [0] due to the "[ ]" you mentioned.

CodePudding user response：

Hope I'm uderstanding it right, but you can use the get() function of dict. For example in your case:

 dict_items = ([('ret_code', 0), ('ret_msg', 'OK'), ('ext_code', ''), ('ext_info', ''), ('result', [{'symbol': 'ETHUSDT', 'bid_price': '1701.8', 'ask_price': '1702', 'last_price': '1704.50', 'last_tick_direction': 'PlusTick', 'prev_price_24h': '1647.55', 'price_24h_pcnt': '0.034566', 'high_price_24h': '1710.55', 'low_price_24h': '1620.40', 'prev_price_1h': '1679.40', 'price_1h_pcnt': '0.014945', 'mark_price': '1702.51', 'index_price': '1702.38', 'open_interest': 150155.81, 'open_value': '0.00', 'total_turnover': '54418340521.33', 'turnover_24h': '63239638.53', 'total_volume': 58525803.73, 'volume_24h': 37976.79, 'funding_rate': '0.0001', 'predicted_funding_rate': '0.0001', 'next_funding_time': '2022-08-25T08:00:00Z', 'countdown_hour': 1, 'delivery_fee_rate': '', 'predicted_delivery_price': '', 'delivery_time': ''}]), ('time_now', '1661411154.330653')])
    
    print(dict_items.get('last_price'))

# Output: 1704.50

CodePudding user response：

If you are dealing with texts, regex might be more appropriate:

import re

text = """dict_items([('ret_code', 0), ('ret_msg', 'OK'), ('ext_code', ''), ('ext_info', ''), ('result', [{'symbol': 'ETHUSDT', 'bid_price': '1701.8', 'ask_price': '1702', 'last_price': '1704.50', 'last_tick_direction': 'PlusTick', 'prev_price_24h': '1647.55', 'price_24h_pcnt': '0.034566', 'high_price_24h': '1710.55', 'low_price_24h': '1620.40', 'prev_price_1h': '1679.40', 'price_1h_pcnt': '0.014945', 'mark_price': '1702.51', 'index_price': '1702.38', 'open_interest': 150155.81, 'open_value': '0.00', 'total_turnover': '54418340521.33', 'turnover_24h': '63239638.53', 'total_volume': 58525803.73, 'volume_24h': 37976.79, 'funding_rate': '0.0001', 'predicted_funding_rate': '0.0001', 'next_funding_time': '2022-08-25T08:00:00Z', 'countdown_hour': 1, 'delivery_fee_rate': '', 'predicted_delivery_price': '', 'delivery_time': ''}]), ('time_now', '1661411154.330653')])"""
last_price_pattern = r"'last_price'\s*:\s*'(\d*\.\d*)'"

last_price = float(re.findall(last_price_pattern, text)[0])
print(last_price)

If you're dealing with a list, then simple indexing will suffice:


raw_data = [('ret_code', 0), ('ret_msg', 'OK'), ('ext_code', ''), ('ext_info', ''), ('result', [{'symbol': 'ETHUSDT', 'bid_price': '1701.8', 'ask_price': '1702', 'last_price': '1704.50', 'last_tick_direction': 'PlusTick', 'prev_price_24h': '1647.55', 'price_24h_pcnt': '0.034566', 'high_price_24h': '1710.55', 'low_price_24h': '1620.40', 'prev_price_1h': '1679.40', 'price_1h_pcnt': '0.014945', 'mark_price': '1702.51', 'index_price': '1702.38', 'open_interest': 150155.81, 'open_value': '0.00', 'total_turnover': '54418340521.33', 'turnover_24h': '63239638.53', 'total_volume': 58525803.73, 'volume_24h': 37976.79, 'funding_rate': '0.0001', 'predicted_funding_rate': '0.0001', 'next_funding_time': '2022-08-25T08:00:00Z', 'countdown_hour': 1, 'delivery_fee_rate': '', 'predicted_delivery_price': '', 'delivery_time': ''}]), ('time_now', '1661411154.330653')]
last_price = float(raw_data[4][1][0]['last_price'])
print(last_price)