Comparing the number of new Python2 and Python3 packages on PyPi

from sys import stdout
from time import sleep, time
import requests
from lxml import html

PYPI_CATEGORIES_URL = 'https://pypi.python.org/pypi?%3Aaction=browse'
PY_VERSIONS_XPATH = '//*[text()="Programming Language :: Python"]/../ul[1]/li'


def fetch():
    while 1:
        resp = requests.get(PYPI_CATEGORIES_URL)
        dom = html.fromstring(resp.text.encode('utf-8'))
        stdout.write('timestamp: {}, '.format(int(time())))
        print(', '.join(': '.join(x.strip().replace(')', '').replace('(', '')
                                  for x in v.xpath('.//text()') if x.strip())
                        for v in dom.xpath(PY_VERSIONS_XPATH)))
        stdout.flush()
        sleep(120)


fetch()

from collections import defaultdict
from datetime import datetime
from sys import argv
import matplotlib.pyplot as plt
from matplotlib.dates import DateFormatter

date_formatter = DateFormatter('%Y.%m.%d\n%H:%M')

data = defaultdict(list)
base = {}
dates = []

tags = ['2', '2.6', '2.7', '3', '3.4', '3.5']

with open(argv[1]) as infile:
    for line in infile.readlines():
        cols = [x.split(': ') for x in line.strip().split(', ')]
        # sometimes PyPi gives empty response, skipping
        try:
            timestamp = int(cols[0][1])
            row_data = dict(x for x in cols[1:] if x[0] in tags)
        except:
            continue

        row_values = defaultdict(int)
        for col_name, col_value in row_data.items():
            c = col_name[0]
            col_value = int(col_value)
            if col_name not in base:
                base[col_name] = col_value

            row_values[c] += col_value-base[col_name]

        # skip lines with same data
        if data and all(data[x][-1] == row_values[x] for x in row_values):
            continue

        for c in row_values:
            data[c].append(row_values[c])
        dates.append(datetime.fromtimestamp(timestamp))


fig, ax = plt.subplots(1)

for py_version in data:
    d = data[py_version]
    plt.plot(dates, data[py_version], label='Python{}'.format(py_version))

plt.legend()
plt.gcf().axes[0].xaxis.set_major_formatter(date_formatter)
ax.set_title("PyPi package number changes")
fig.savefig('xy.png')