Python Tutorial

Friday, May 13, 2016

Selenium unittest example


import unittest
from selenium import webdriver
from selenium.webdriver.common.keys import Keys

class JPythonSearch(unittest.TestCase):

    def setUp(self):
        self.driver = webdriver.Firefox()

    def test_search_in_python_org(self):
     URL = "http://jpython.blogspot.com"
        driver = self.driver
        driver.get(URL)
        self.assertIn("Life is very easy with Python", driver.title)
        elem = driver.find_element_by_name("q")
        elem.send_keys("BFS")
        elem.send_keys(Keys.RETURN)
        assert "No results found." not in driver.page_source


    def tearDown(self):
        self.driver.close()

if __name__ == "__main__":
    unittest.main()

Output:

.
----------------------------------------------------------------------
Ran 1 test in 25.592s

OK
[Finished in 25.7s]

Selenium example

Here I am showing the example of browse and search into a site programmatically.
from selenium import webdriver
from selenium.webdriver.common.keys import Keys

URL = "http://jpython.blogspot.com"
driver = webdriver.Firefox()
driver.get(URL)
print driver.title


search = driver.find_element_by_name("q") # find search field
search.send_keys("BFS") # set search key
search.send_keys(Keys.RETURN) # hit enter

driver.implicitly_wait(10) # wait 10 seconds
driver.close()

Output:

Life is very easy with Python

Selenium installation

Selenium Python bindings provides a simple API to write functional/acceptance tests using Selenium WebDriver. Through Selenium Python API you can access all functionalities of Selenium WebDriver in an intuitive way.

Installation

pip install selenium

If you don't have pip installed try this

Wednesday, November 11, 2015

map keyword

Apply function to every item of iterable and return a list of the results. If additional iterable arguments are passed, function must take that many arguments and is applied to the items from all iterables in parallel. If one iterable is shorter than another it is assumed to be extended with None items.


All source code available on github
intArray = [2, 3, 4, 6, 5, 7]
strArray = ['2', '3', '4', '6', '5', '7']

# square all elements of array
print map(lambda x:x**2, intArray)

# convert string array to int array
print map(int, strArray)

a = [1, 2, 3]
b = [4, 5, 6]

# sum two array elements  by index
print map(lambda x, y : x+y, a, b)


Output:
[4, 9, 16, 36, 25, 49]
[2, 3, 4, 6, 5, 7]
[5, 7, 9]

Monday, October 19, 2015

Dijkstra algorithm


Dijkstra algorithm is a single source shortest path algorithm. For a given source node in the graph, the algorithm finds the shortest path between that node and every other.

Here is the python implementation of Dijkstra algorithm
from heapq import heappush, heappop

# 0 index base dijkstra algorithm
def Dijkstra(graph, source):
    A = [None] * len(graph)
    queue = [(0, source)]
    while queue:
        path_len, v = heappop(queue)
        if A[v] is None: # v is unvisited
            A[v] = path_len
            for w, edge_len in graph[v].items():
                if A[w] is None:
                    heappush(queue, (path_len + edge_len, w))

    # set -1 for unreachable           
    return [-1 if x is None else x for x in A] 

graph = {
  0: { 1:2, 2:4, 3:1 },
  1: { 2:1, 3:3 },
  2: { 4: 7},
  3: { 2: 2 },
  4: { 0:2, 3:3 }, 
  5: {}
}
source = 0

print Dijkstra(graph, source)

Output:
[0, 2, 3, 1, 10, -1]

Saturday, October 17, 2015

python heapq/priority queue/Min heap


Python heapq provides implementation of the heap(min) queue algorithm, also known as the priority queue algorithm. Here's some example code.
from heapq import heappush, heappop

# priority queue normal
h = []
heappush(h, 5)
heappush(h, 1)
heappush(h, 3)

print heappop(h),"size",len(h)
print heappop(h),"size",len(h)
print heappop(h),"size",len(h)

# priority queue with tuple number and string
h = []
heappush(h, (5, "sample text"))
heappush(h, (1, "important text"))
heappush(h, (1, "a important text"))
heappush(h, (9, "un-important text"))

print heappop(h)
print heappop(h)

# priority queue with tuple number only 
h = []
heappush(h, (5, 3))
heappush(h, (7, 3))
heappush(h, (1, 3))
heappush(h, (1, 1))
heappush(h, (1, 2))
heappush(h, (3, 2))
heappush(h, (3, 1))

print heappop(h)
print heappop(h)
print heappop(h)

Output:
1 size 2
3 size 1
5 size 0
(1, 'a important text')
(1, 'important text')
(1, 1)
(1, 2)
(1, 3)

Saturday, August 1, 2015

Improve python programming/problem solving skill


Sites that will improve your python programming skill.
I will update this list regularly & open to any suggestion,