weird error - increasing month by one - Python+MySQL - mysql

Question

2017-05-12 is inserted in to MySQL as 2017-06-12 - couldn't figure out with debugging...pasted the key parts of code
Windows platform; Used PyMySQL; If the issue isnt resolved, i will probably bulk update the table to reduce the month by one...i guess that should be easy...
exceptions = []
flag = 'N'
def obtain_list_of_db_tickers():
"""
Obtains a list of the ticker symbols in the database.
"""
with con:
cur = con.cursor()
cur.execute("SELECT id, ticker FROM symbol")
data = cur.fetchall()
list1,list2 = map(list,zip(*data))
uniqtickers = list(set(list2))
rangelist = list(range(1,len(uniqtickers)+1))
newtickers = list(zip(rangelist,uniqtickers))
return [(d[0], d[1]) for d in newtickers]
def get_daily_historic_data_yahoo(
ticker, start_date=(2017,5,12),
end_date=datetime.date.today().timetuple()[0:3]
) :
""""
Obtains data from Yahoo Finance returns and a list of tuples
ticker: Yahoo Finance ticker symbol eg: GOOG
start_date: Start date in (YYYY,M,D) format
End_date: End date in (YYYY,M,D) format
"""
# Construct the Yahoo URL with the correct integer query parameters
# for start and end dates. Note that some parameters are zero-based!
ticker_tup = (
ticker, start_date[1]-1, start_date[2],
start_date[0], end_date[1]-1, end_date[2],
end_date[0]
)
yahoo_url = "http://ichart.finance.yahoo.com/table.csv"
yahoo_url += "?s=%s&a=%s&b=%s&c=%s&d=%s&e=%s&f=%s"
yahoo_url = yahoo_url % ticker_tup
# Try connecting to Yahoo Finance and obtaining the data
# On failure, print an error message.
global flag
try:
yf_data = pd.read_csv(yahoo_url)
yf_data['Date'] = yf_data['Date'].apply(lambda x:
datetime.datetime.strptime(x, '%Y-%m-%d'))
prices = yf_data.set_index(['Date'])[['Open', 'High', 'Low', 'Close',
'Volume', 'Adj Close']].to_records().tolist()
except Exception as e:
print("Could not download Yahoo data: %s" %e)
flag = 'Y'
exceptions.append(ticker)
return None
return prices
def insert_daily_data_into_db(
data_vendor_id, symbol_id, ticker, daily_data
):
"""
Takes a list of tuples of daily data and adds it to the
MySQL database. Appends the vendor ID and symbol ID to the data.
daily_data: List of tuples of the OHLC data(with adj_close and volume)
"""
# Create the time now
now = datetime.datetime.utcnow()
#Amend the data to include the vendor ID and symbol IDprices
daily_data = [
(data_vendor_id, symbol_id, ticker, d[0], now, now,
d[1], d[2], d[3], d[4], d[5], d[6])
for d in daily_data
]
# Create the insert strings
column_str = """data_vendor_id, symbol_id, ticker, price_date, created_date,
last_updated_date, open_price, high_price, low_price,
close_price, volume, adj_close_price"""
insert_str = ("%s, " *12)[:-2]
final_str = "INSERT INTO daily_price (%s) VALUES (%s)" %\
(column_str, insert_str)
# Using the MySQL connection, carry out an INSERT INTO for every symbol
with con:
cur = con.cursor()
cur.executemany(final_str, daily_data)
if __name__ == "__main__":
# This ignores the warnings regarding Data Truncation
# from the Yahoo precision to Decimal(19,4) datatypes
warnings.filterwarnings('ignore')
# Loop over the tickers and insert the daily historical
# data into the database
tickers = obtain_list_of_db_tickers()
lentickers = len(tickers)
for i, t in enumerate(tickers):
print(
"Adding data for %s: %s out of %s" %
(t[1], i+1, lentickers)
)
yf_data = get_daily_historic_data_yahoo(t[1])
if (flag == 'N'):
insert_daily_data_into_db('1', t[0], t[1], yf_data)
elif (flag == 'Y'):
flag = 'N'