How to filter list element in Python based on another list?-CodePudding

I have a list of dictionaries, and would like to split the dictionaries based on the value of key "timestamp". The idea is to group dictionaries of semester 1 (January to July) and dictionaries of semester 2 (August to December). How can I do that in a performance-effective manner?

This is my code:

group1 = ['2020-01', '2020-02', '2020-03', '2020-04', '2020-05', '2020-06']

data = [
    {
        'timestamp': '2020-01-01T00:00:00Z',
        'price': 7204.54,
        'volume_24h': 13086960135,
        'market_cap': 130644686531},
    {
        'timestamp': '2020-01-01T01:00:00Z',
        'price': 7218.55,
        'volume_24h': 13133228186,
        'market_cap': 130899528700},
    {
        'timestamp': '2020-01-01T02:00:00Z',
        'price': 7241.8,
        'volume_24h': 13257849556,
        'market_cap': 131321418482
    }
]

semester_1 = [i for i in data if group1 in i['timestamp']]

Unfortunately, it throws an error because group1 is a list.

CodePudding user response：

You can try to check if the substring of timestamp including that date is in the list group1:

group1 = [f'2020-0{i}' for i in range(1,7)]

data = [{'timestamp': '2020-01-01T00:00:00Z',
  'price': 7204.54,
  'volume_24h': 13086960135,
  'market_cap': 130644686531},
 {'timestamp': '2020-01-01T01:00:00Z',
  'price': 7218.55,
  'volume_24h': 13133228186,
  'market_cap': 130899528700},
 {'timestamp': '2020-01-01T02:00:00Z',
  'price': 7241.8,
  'volume_24h': 13257849556,
  'market_cap': 131321418482}]

semester_1 = [item for item in data if item['timestamp'][:7] in group1]

CodePudding user response：

Try:

semester_1 = [i for i in data if i['timestamp'][0:7] in group1]

Or even without defininig group1:

semester_1 = [i for i in data if int(i['timestamp'][5:7]) < 7]