How to use the otree.api.models.CharField function in otree

from otree.api import models
from otree.db.models import Model, ForeignKey
from . import market_environments
from django.utils import timezone
import logging

log = logging.getLogger(__name__)



class TimeAwareInSessionRecord(Model):
    timestamp = models.DateTimeField(default=timezone.now)
    trigger_event_type = models.CharField()
    event_no = models.IntegerField()
    subsession_id = models.IntegerField()
    market_id = models.IntegerField()


class TraderRecord(TimeAwareInSessionRecord):
    
    csv_meta = (
    'timestamp', 'subsession_id', 'market_id', 'player_id', 'trigger_event_type',
    'event_no',  'trader_model_name', 'inventory', 'bid', 'offer', 
    'best_bid_except_me', 'best_offer_except_me',
    'delay', 'staged_bid', 'staged_offer', 'implied_bid', 
    'implied_offer', 'slider_a_x','slider_a_y', 'slider_a_z',
    'net_worth', 'cash', 'tax_paid', 'speed_cost', 'midpoint_peg', 'peg_price', 'peg_state')

    # timestamp = models.DateTimeField(default=timezone.now)

json_fields = {}
            for field in self._meta.get_fields():
                if isinstance(field, JSONField):
                    json_fields[field.attname] = getattr(self, field.attname)
            self.__class__._default_manager.filter(pk=self.pk).update(**json_fields)


class Group(BaseGroup):
    pass


class Player(BasePlayer):

    channel = models.CharField(max_length=255)
    consented = models.BooleanField(initial=False)
    exchange_host = models.CharField()
    exchange_port = models.IntegerField()
    # subsession_id = models.CharField()
    market_id = models.CharField()
    id_in_market = models.IntegerField()
    speed_unit_cost = models.IntegerField()
    net_worth = models.IntegerField()
    cash = models.IntegerField()
    cost = models.IntegerField()
    speed_cost = models.IntegerField()
    tax_paid = models.IntegerField()
    reference_price = models.IntegerField()
    inventory = models.IntegerField()
    bid = models.IntegerField()
    offer = models.IntegerField()
    staged_bid = models.IntegerField()
    staged_offer = models.IntegerField()

'survey_fields': [  # we define two forms here ...
            {   # ... this one is shown when player.treatment == 1 ...
                'form_name': 'treatment_1_form',
                'fields': [
                    ('q_treatment_1', {
                        'text': 'This is a question for treatment 1: Do you feel tired?',
                        'field': models.CharField(choices=YESNO_CHOICES, blank=True),
                    }),
                ]
            },
            {   # ... this one is shown when player.treatment == 2 ...
                'form_name': 'treatment_2_form',  # optional, can be used for CSS styling
                'fields': [
                    ('q_treatment_2', {
                        'text': "This is a question for treatment 2:  Don't you feel tired?",
                        'field': models.CharField(choices=YESNO_CHOICES, blank=True),
                    }),
                ]
            },
        ]
    },
    {
        'page_title': 'Survey Questions - Page 6 - Conditional fields and widget adjustments',
        'form_help_initial': """
            <p>Conditional fields can be made with the <code>condition_javascript</code> parameter,
            widget adjustments like custom CSS styles can be controlled via <code>widget_attrs</code>.</p>""",
        'survey_fields': [
            ('q_uses_ebay', {
                'text': 'Do you sell things on eBay?',
                'field': models.CharField(choices=YESNO_CHOICES),
            }),
            ('q_ebay_member_years', {

from .dispatcher import DispatcherFactory

log = logging.getLogger(__name__)

class Constants(BaseConstants):
    name_in_url = 'hft'
    players_per_group = None
    num_rounds = 3


class Subsession(BaseSubsession):
    model_name = models.StringField(initial='subsession')
    auction_format = models.StringField()
    session_duration = models.IntegerField()
    batch_length = models.IntegerField(initial=0)
    code = models.CharField(default=random_chars_8)

    def creating_session(self):
        def create_trade_session(session_format):
            trade_session_cls = TradeSessionFactory.get_session(session_format)
            dispatcher = DispatcherFactory.get_dispatcher(session_format)
            trade_session = trade_session_cls(self, session_format, dispatcher)
            environment = market_environments.environments[session_format]
            for event_type in environment.exogenous_events:
                event_filename = self.session.config[event_type].pop(0)
                trade_session.register_exogenous_event(
                    event_type, event_filename)
            return trade_session
        session_format = self.session.config['environment']    
        if self.round_number == 1:
            self.session.config = utility.process_configs(
                session_format, self.session.config)

try:
                        process.kill()
                    except Exception as e:
                        log.exception(e)




class Subsession(BaseSubsession):
    design = models.StringField()
    next_available_exchange = models.IntegerField()
    players_per_group = models.IntegerField()
    round_length = models.IntegerField()
    batch_length = models.IntegerField(initial=0)
    trade_ended = models.BooleanField(initial=False)
    code = models.CharField(default=random_chars_8)
    has_trial = models.BooleanField(initial=True)
    is_trial = models.BooleanField(initial=False)
    trial_length = models.IntegerField(initial=0)
    log_file = models.StringField()
    first_round = models.IntegerField(initial=1)
    last_round = models.IntegerField(initial=0)
    total_rounds = models.IntegerField(initial=0)
    restore_from = models.CharField()
    restore = models.BooleanField(initial=False)
    lambda_i = models.FloatField()
    lambda_j = models.FloatField()

    def init_cache(self):
        pairs = {}
        session_lock = Constants.lock_key.format(self=self)
        pairs[session_lock] = Constants.unlock_value

super().save(*args, **kwargs)
        if self.pk is not None:
            json_fields = {}
            for field in self._meta.get_fields():
                if isinstance(field, JSONField):
                    json_fields[field.attname] = getattr(self, field.attname)
            self.__class__._default_manager.filter(pk=self.pk).update(**json_fields)


class Group(BaseGroup):
    pass


class Player(BasePlayer):

    channel = models.CharField(max_length=255)
    consented = models.BooleanField(initial=False)
    exchange_host = models.CharField()
    exchange_port = models.IntegerField()
    # subsession_id = models.CharField()
    market_id = models.CharField()
    id_in_market = models.IntegerField()
    speed_unit_cost = models.IntegerField()
    net_worth = models.IntegerField()
    cash = models.IntegerField()
    cost = models.IntegerField()
    speed_cost = models.IntegerField()
    tax_paid = models.IntegerField()
    reference_price = models.IntegerField()
    inventory = models.IntegerField()
    bid = models.IntegerField()
    offer = models.IntegerField()

# basic state variables
    role = models.StringField(initial='OUT')
    speed = models.BooleanField(initial=False)
    spread = models.IntegerField()
    channel = models.CharField(max_length=255)
    cost = models.IntegerField(initial=0)
    fp = models.IntegerField()
    endowment = models.IntegerField()
    prev_speed_update = models.BigIntegerField(initial=0)
    speed_on = models.IntegerField(initial=0)
    speed_unit_cost = models.IntegerField()
    max_spread = models.IntegerField()
    code = models.CharField(default=random_chars_8)
    log_file = models.StringField()
    design =  models.CharField()
    consent = models.BooleanField(initial=True)
    final_payoff = models.IntegerField()
    total_payoff = models.IntegerField()

    def init_cache(self):
        pairs = {}
        lock_key = Constants.lock_key.format(self=self)
        pairs[lock_key] = Constants.unlock_value
        orderstore_key = Constants.player_orderstore_key.format(self=self)
        pairs[orderstore_key] = OrderStore(self.id, self.id_in_group)
        state_key = Constants.player_status_key.format(self=self)
        role_key = Constants.player_role_key.format(self=self)
        pairs[role_key] = self.role.lower()
        kwargs = {k: getattr(self, k, None) for k in Constants.player_fields}
        exchange_address = '{}:{}'.format(self.group.exch_host, self.group.exch_port)
        kwargs.update({'exchange_address':exchange_address, 'group_id': self.group.id})

json_fields = {}
            for field in self._meta.get_fields():
                if isinstance(field, JSONField):
                    json_fields[field.attname] = getattr(self, field.attname)
            self.__class__._default_manager.filter(pk=self.pk).update(**json_fields)

translator = new_translator.Translator()

class Group(BaseGroup):

    exch_host = models.StringField()
    exch_port = models.IntegerField()
    investor_file = models.StringField()
    jump_file = models.StringField()
    is_trading = models.BooleanField(initial=False)
    code = models.CharField(default=random_chars_8)
    log_file = models.StringField()

    def init_cache(self):
        pairs = {}
        group_lock = Constants.lock_key.format(self=self)
        pairs[group_lock] = Constants.unlock_value
        in_market_key= Constants.players_in_market_key.format(self=self)   
        pairs[in_market_key] = {p.id: False for p in self.get_players()}
        role_count_key = Constants.role_count_key.format(self=self)
        pairs[role_count_key] = {k: getattr(self.subsession, v) if isinstance(v, str) else v
                                    for k, v in Constants.group_role_counts.items()} 
        for k, v in pairs.items():
            cache.set(k, v, timeout=None)

)
        if total != ppg:
            raise ValueError('total: %d, ppg: %d' % (total, ppg))

    def loggy(self):
        log_events.convert()
        log_events.dump()


class Player(BasePlayer):

    # basic state variables
    role = models.StringField(initial='OUT')
    speed = models.BooleanField(initial=False)
    spread = models.IntegerField()
    channel = models.CharField(max_length=255)
    cost = models.IntegerField(initial=0)
    fp = models.IntegerField()
    endowment = models.IntegerField()
    prev_speed_update = models.BigIntegerField(initial=0)
    speed_on = models.IntegerField(initial=0)
    speed_unit_cost = models.IntegerField()
    max_spread = models.IntegerField()
    code = models.CharField(default=random_chars_8)
    log_file = models.StringField()
    design =  models.CharField()
    consent = models.BooleanField(initial=True)
    final_payoff = models.IntegerField()
    total_payoff = models.IntegerField()

    def init_cache(self):
        pairs = {}

csv_meta = (
    'timestamp', 'subsession_id', 'market_id', 'player_id', 'trigger_event_type',
    'event_no',  'trader_model_name', 'inventory', 'bid', 'offer', 
    'best_bid_except_me', 'best_offer_except_me',
    'delay', 'staged_bid', 'staged_offer', 'implied_bid', 
    'implied_offer', 'slider_a_x','slider_a_y', 'slider_a_z',
    'net_worth', 'cash', 'tax_paid', 'speed_cost', 'midpoint_peg', 'peg_price', 'peg_state')

    # timestamp = models.DateTimeField(default=timezone.now)
    # trigger_event_type = models.CharField()
    # event_no = models.IntegerField()
    # subsession_id = models.IntegerField()
    # market_id = models.IntegerField()
    player_id = models.IntegerField()
    trader_model_name =  models.CharField()
    delay = models.FloatField()
    net_worth = models.IntegerField()
    cash = models.IntegerField()
    cost = models.IntegerField()
    speed_cost = models.IntegerField()
    tax_paid = models.IntegerField()
    reference_price = models.IntegerField()
    inventory = models.IntegerField()
    bid = models.IntegerField()
    offer = models.IntegerField()
    staged_bid = models.IntegerField()
    staged_offer = models.IntegerField()
    implied_bid = models.IntegerField()
    implied_offer = models.IntegerField()
    best_bid = models.IntegerField()
    best_offer = models.IntegerField()