[FIXED] how to use datestr2num instead of strpdate2num

Issue

The strpdate2num class was deprecated in Matplotlib 3.1 and will be removed in 3.3. Use time.strptime or dateutil.parser.parse or datestr2num instead. However i tried different method and just keep getting error, the most common error message is ValueError: ('Unknown string format:', '%Y-%m-%d')

i have tried time.strptime, dateutil.parser.parse and datestr2num, but none of those are correct, i have no idea what i get wrong

import matplotlib.pyplot as plt
import numpy as np
import urllib.request
import matplotlib.dates as mdates

def bytespdate2num(fmt, encoding='utf-8'):
    strconverter = mdates.datestr2num(fmt)
    def bytesconverter(b):
        s = b.decode(encoding)
        return strconverter(s)
    return bytesconverter


def graph_data(stock):
    # Unfortunately, Yahoo's API is no longer available
    # feel free to adapt the code to another source, or use this drop-in replacement.
    stock_price_url = 'https://pythonprogramming.net/yahoo_finance_replacement'
    source_code = urllib.request.urlopen(stock_price_url).read().decode()
    stock_data = []
    split_source = source_code.split('\n')
    for line in split_source[1:]:
        split_line = line.split(',')
        if len(split_line) == 7:
            if 'values' not in line and 'labels' not in line:
                stock_data.append(line)

    date, closep, highp, lowp, openp, adj_closep, volume = np.loadtxt(  stock_data,
                                                                        delimiter=',',
                                                                        unpack=True,
                                                                        # %Y = full year. 2015
                                                                        # %y = partial year 15
                                                                        # %m = number month
                                                                        # %d = number day
                                                                        # %H = hours
                                                                        # %M = minutes
                                                                        # %S = seconds
                                                                        # 12-06-2014
                                                                        # %m-%d-%Y
                                                                        converters={0: bytespdate2num('%Y-%m-%d')})

    plt.plot_date(date, closep,'-', label='Price')

    plt.xlabel('Date')
    plt.ylabel('Price')
    plt.title('Interesting Graph\nCheck it out')
    plt.legend()
    plt.show()


graph_data('TSLA')

ValueError: ('Unknown string format:', '%Y-%m-%d')

Solution

Your dateformat seems quite common, so strconverter = mdates.datestr2num should work (no fmt argument). Of course in that case the complete converter can be simplified to

def bytespdate2num(b):
    return mdates.datestr2num(b.decode('utf-8'))

and use it like

converters={0: bytespdate2num}

Answered By - ImportanceOfBeingErnest