matplotlib timestamp

[zero_shubh0]

I'm not able to attach my code here. 
This is about converting standard date formats to matplotlib's own kind of format (something gregorian calendar related), I tried to solve it by reading about it in the official documentation but that was too much to swallow. If anyone here has a basic concept about it, please help with a healthy discussion down there. Thank you!

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http://pastebin.com/u2Yk3EGD  My code.

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

def bytespdate2num(fmt, encoding='utf-8'):
   strconverter = mdates.strpdate2num(fmt)
   def bytesconverter(b):
       s = b.decode(encoding)
       return strconverter(s)
   return bytesconverter
   

def graph_data(stock):

   stock_price_url = 'http://chartapi.finance.yahoo.com/instrument/1.0/'+stock+'/chartdata;type=quote;range=10y/csv'
   source_code = urllib.request.urlopen(stock_price_url).read().decode()
   stock_data = []
   split_source = source_code.split('\n')
   for line in split_source:
       split_line = line.split(',')
       if len(split_line) == 6:
           if 'values' not in line and 'labels' not in line:
               stock_data.append(line)

   date, closep, highp, lowp, openp, 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')

Even if you are able to make me understand the working of 'bytespdate2num' function in the above code will be helpful.

[heiner55]

You can code your own converter.
Then it is easier to understand what is going on:

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

# convert "yyyymmdd" to float
def yyyymmdd2num(s):
    return mdates.date2num(datetime.datetime(int(s[0:4]), int(s[4:6]), int(s[6:8])))

def graph_data(stock):
   stock_price_url = 'http://chartapi.finance.yahoo.com/instrument/1.0/'+stock+'/chartdata;type=quote;range=10y/csv'
   source_code = urllib.request.urlopen(stock_price_url).read().decode()
   stock_data = []
   split_source = source_code.split('\n')
   for line in split_source:
       split_line = line.split(',')
       if len(split_line) == 6:
           if 'values' not in line and 'labels' not in line:
               stock_data.append(line)

   date, closep, highp, lowp, openp, volume = np.loadtxt(stock_data,
                                                         delimiter=',',
                                                         unpack=True,
                                                         converters={0: yyyymmdd2num}) # converter for column 0

   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')

[zero_shubh0]

What i know is that matplotlib doesn't supports the standard dates, it has some other formats. Have tried running it in the interpreter?