def sell(ticker_symbol, trade_volume, username):
trade_volume = float(trade_volume)
user_balance = mapper.select_balance(username)
ticker_symbols = mapper.select_ticker(ticker_symbol, username)
brokerage_fee = 6.95
last_price = wrapper.get_last_price(ticker_symbol)
transaction_cost = (last_price * trade_volume) - brokerage_fee
if ticker_symbols != None: # If the holding exists. Continue...
x = mapper.select_holding(ticker_symbol, username)
prev_volume = float(x[0])
vwap = float(x[1])
total_vol = prev_volume - trade_volume
new_balance = user_balance + transaction_cost
if prev_volume > trade_volume:
mapper.update_holdings(total_vol, vwap, ticker_symbol, username)
mrkt_value = market_value(username)
new_mrkt_val = mrkt_value + new_balance
mapper.update_balance(new_balance, new_mrkt_val, username)
elif prev_volume == trade_volume:
mapper.delete_holding(ticker_symbol, username)
mrkt_value = market_value(username)
new_mrkt_val = mrkt_value + new_balance
mapper.update_balance(new_balance, new_mrkt_val, username)
elif prev_volume < trade_volume:
return 'You do not have that many shares!'
return 'Successful!'
else:
return 'You do not have that stock!'
def buy(ticker_symbol, trade_volume, username):
trade_volume = float(trade_volume)
user_balance = mapper.select_balance(username)
brokerage_fee = 6.95
last_price = wrapper.get_last_price(ticker_symbol)
print(last_price)
transaction_cost = (last_price * float(trade_volume)) + brokerage_fee
if user_balance >= transaction_cost:
ticker_symbols = mapper.select_ticker(ticker_symbol, username)
if ticker_symbols == None: # If the holding exists. Continue...
mapper.insert_to_holdings(ticker_symbol, trade_volume, last_price,
username)
else:
x = mapper.select_holding(ticker_symbol, username)
prev_volume = float(x[0])
prev_price = float(x[1])
# Calculating VWAP
old = prev_volume * prev_price
new = trade_volume * last_price
total_vol = prev_volume + trade_volume
new_vwap = (old + new) / (total_vol)
mapper.update_holdings(total_vol, new_vwap, ticker_symbol,
username)
new_balance = user_balance - transaction_cost
mrkt_value = market_value(username)
new_mrkt_val = mrkt_value + new_balance
mapper.update_balance(new_balance, new_mrkt_val, username)
return 'Successful!'
else:
return 'Error: You do not have enough money to trade!'
def sell(ticker_symbol, trade_volume, username):
last_price = wrapper.get_last_price(ticker_symbol)
# Error handling: if the user enters a ticker symbol that does not exist.
if last_price == "exit":
print("The ticker symbol that you entered does not exist.")
return "exit"
brokerage_fee = 6.95
# Error handling: if the user enters a trade volume that is not a number.
try:
balance_to_add = last_price * float(trade_volume) - brokerage_fee
except ValueError:
print("The trade volume you entered is not valid.")
return "exit"
# Checks if the user holds any stock from the company with ticker_symbol.
ticker_symbols = mapper.get_ticker_symbols(ticker_symbol, username)
if len(ticker_symbols) == 0:
return "Error: You do not hold any shares from that company."
# Gets needed values from the user and holdings database tables.
balance = mapper.get_balance(username)
number_of_shares = mapper.get_number_of_shares(ticker_symbol, username)
new_number_of_shares = number_of_shares - int(trade_volume)
# If the user holds enough shares to complete their trade.
if int(trade_volume) <= number_of_shares:
# If the new number of shares would be 0 after the user sells their shares.
if new_number_of_shares == 0:
# Deletes the row from holdings database table for company with ticker_symbol.
mapper.delete_holdings_row(ticker_symbol)
else:
# Updates holdings database table with the new number of shares.
mapper.update_number_of_shares(new_number_of_shares, ticker_symbol, username)
# Gets the last price stored in the holdings database table for a given ticker_symbol.
curr_price = mapper.get_last_price(ticker_symbol, username)
# Gets the number of shares from holdings database table for the company with ticker_symbol.
curr_number_of_shares = mapper.get_number_of_shares(ticker_symbol, username)
# Calculates the new VWAP based on old values in the database table.
new_vwap = calculate_vwap(curr_price, curr_number_of_shares, last_price, trade_volume)
# Updates the VWAP in the holdings database table with a new value.
mapper.update_volume_weighted_average_price(new_vwap, ticker_symbol, username)
# Updates users database table with the new balance after selling the stock.
new_balance = balance + balance_to_add
mapper.update_balance(new_balance, username)
# Inserts a new row to the orders database table after selling the stock.
mapper.insert_orders_row("sell", ticker_symbol, trade_volume, last_price, username)
return "Stock sell was successful."
else:
# Returns error response.
return "Error: You do not have enough shares to sell to complete that trade."
def buy(ticker_symbol, trade_volume, username):
last_price = wrapper.get_last_price(ticker_symbol)
# Error handling: if the user enters a ticker symbol that does not exist.
if last_price == "exit":
print("The ticker symbol that you entered does not exist.")
return "exit"
balance = mapper.get_balance(username)
brokerage_fee = 6.95
# Error handling: if the user enters a trade volume that is not a number.
try:
transaction_cost = last_price * float(trade_volume) + brokerage_fee
except ValueError:
print("The trade volume you entered is not valid.")
return "exit"
# If the user has enough money in their account to execute the trade.
if transaction_cost < balance:
ticker_symbols = mapper.get_ticker_symbols(ticker_symbol, username)
# If the user does not hold any stock from company with ticker_symbol.
if len(ticker_symbols) == 0:
new_balance = balance - transaction_cost
# Updates the user's balance in the users database table.
mapper.update_balance(new_balance, username)
# Inserts a new row to the holdings database table after buying the stock.
mapper.insert_holdings_row(ticker_symbol, trade_volume, last_price, username)
# Inserts a new row to the orders database table after buying the stock.
mapper.insert_orders_row("buy", ticker_symbol, trade_volume, last_price, username)
return "Stock purchase was successful."
# If the user holds some stock from company with ticker_symbol.
else:
# Gets the number of shares from holdings database table for the company with ticker_symbol.
curr_number_of_shares = mapper.get_number_of_shares(ticker_symbol, username)
new_number_of_shares = curr_number_of_shares + int(trade_volume)
# Gets the last price stored in the holdings database table for a given ticker_symbol.
curr_price = mapper.get_last_price(ticker_symbol, username)
# Calculates the new VWAP based on the current values in the database table and the most recent (last) prices.
new_vwap = calculate_vwap(curr_price, curr_number_of_shares, last_price, trade_volume)
# Updates the VWAP in the holdings database table with a new value.
mapper.update_volume_weighted_average_price(new_vwap, ticker_symbol, username)
# Updates the holdings database table with the new number of shares after buying stock.
mapper.update_number_of_shares(new_number_of_shares, ticker_symbol, username)
# Inserts a new row to the orders database table after buying the stock.
mapper.insert_orders_row("buy", ticker_symbol, trade_volume, last_price, username)
return "Stock purchase was successful."
else:
# Returns error response.
return "Error: You do not have enough money in your balance to execute that trade."
def update_balance(username, balance):
return mapper.update_balance(username, balance)
def update_balance(new_balance, username): return mapper.update_balance(new_balance, username)