So I am currently working on a coding lab where my goal is to try to combine multiple mapping into a single mapping
Eng_Team = [
{'player': 'Harry Kane', 'rating': '90'},
{'player': 'Harry Mcguire', 'rating': '81'},
{'player': 'Phil Foden', 'rating': '84'},
{'player': 'Jack Grealish', 'rating': '85'},
{'player': 'Eric Dier', 'rating': '79'}
]
USA_Team = [
{'player': 'Christian Pulisic', 'rating': '82'},
{'player': 'Gio Reyna', 'rating': '79'},
{'player': 'Weston Mckinnie', 'rating': '78'},
{'player': 'Sergino Dest', 'rating': '79'},
{'player': 'Tyler Adams', 'rating': '79'}
]
I tried
player_lookup = ChainMap(USA_Team,Eng_Team)
print(player_lookup['player'])
to try to get the names of players from both dictionaries. However I am getting this error:
TypeError Traceback (most recent call last)
Input In [49], in <cell line: 5>()
1 from collections import ChainMap
3 player_lookup = ChainMap(USA_Team,Eng_Team)
----> 5 print(player_lookup['player'])
File ~\anaconda3\lib\collections\__init__.py:938, in ChainMap.__getitem__(self, key)
936 for mapping in self.maps:
937 try:
--> 938 return mapping[key] # can't use 'key in mapping' with defaultdict
939 except KeyError:
940 pass
TypeError: list indices must be integers or slices, not str
It is to my knowledge that I might have to create a loop function. How would I do so?
CodePudding user response：
You were probabably after something like this:
from collections import ChainMap
# this is not a dictionary, but a list of dictionaries
# so, eng_team['player'] wouldn't actually work
eng_team = [
{'player': 'Harry Kane', 'rating': '90'},
{'player': 'Harry Mcguire', 'rating': '81'},
{'player': 'Phil Foden', 'rating': '84'},
{'player': 'Jack Grealish', 'rating': '85'},
{'player': 'Eric Dier', 'rating': '79'},
{'player': 'John Doe', 'rating': 0}
]
# this is also a list of dictionaries, not a dictionary
usa_team = [
{'player': 'Christian Pulisic', 'rating': '82'},
{'player': 'Gio Reyna', 'rating': '79'},
{'player': 'Weston Mckinnie', 'rating': '78'},
{'player': 'Sergino Dest', 'rating': '79'},
{'player': 'Tyler Adams', 'rating': '79'},
{'player': 'John Doe', 'rating': 1}
]
# so, you'd want to create appropriate dictionaries from the data
# (unless you can just define them as dictionaries right away)
eng_team_dict = {p['player']: {**p} for p in eng_team}
usa_team_dict = {p['player']: {**p} for p in usa_team}
# the dictionaries can be chain-mapped
all_players = ChainMap(eng_team_dict, usa_team_dict)
# this then works
print(all_players['Harry Kane'], all_players['Sergino Dest'])
print(list(all_players.keys()))
# note that dupplicate keys will be taken from the first dict in
# the arguments to ChainMap, i.e. `eng_team_dict` in this case
print(all_players['John Doe'])
Output:
{'player': 'Harry Kane', 'rating': '90'} {'player': 'Sergino Dest', 'rating': '79'}
['Christian Pulisic', 'Gio Reyna', 'Weston Mckinnie', 'Sergino Dest', 'Tyler Adams', 'John Doe', 'Harry Kane', 'Harry Mcguire', 'Phil Foden', 'Jack Grealish', 'Eric Dier']
{'player': 'John Doe', 'rating': 0}
CodePudding user response：
I think what you're getting stuck on is that you have declared two lists of dictionaries: not two dictionaries. I believe that if you want to combine them into one dictionary you could use something like
player_rating_lookup = {}
for player_dictionary in Eng_Team:
player_rating_lookup[player_dictionary['player']] = player_dictionary['rating']
# adds to the player_rating_lookup dictionary:
# the player name string is the key in this new dictionary, and the rating string is the value.
for player_dictionary in USA_Team:
player_rating_lookup[player_dictionary['player']] = player_dictionary['rating']
# you can just iterate over the two lists of dictionaries separately.
CodePudding user response：
What you are looking for should really be a dict that maps each player's name to its rating, in which case you can chain the two lists of dicts, map the dicts to an itemgetter to produce a sequence of tuples of player name and rating, and then construct a new dict with the sequence:
from operator import itemgetter
from itertools import chain
dict(map(itemgetter('player', 'rating'), chain(Eng_Team, USA_Team)))
This returns:
{'Harry Kane': '90', 'Harry Mcguire': '81', 'Phil Foden': '84', 'Jack Grealish': '85', 'Eric Dier': '79', 'Christian Pulisic': '82', 'Gio Reyna': '79', 'Weston Mckinnie': '78', 'Sergino Dest': '79', 'Tyler Adams': '79'}