#!/usr/bin/env python
# coding: utf-8

# ### Simple while loop

# In[ ]:


n = 23
r = True

while r:
    guess= int(input('Enter an integer: '))
    
    if guess == n:
        print('yes')
        r = False
    elif guess < n:
        print('no')
    else:
        print('no1')
else:
    print('done')
    
print('yes done')        


# ## Simple backup

# In[9]:


import os
import time

source = '/home/akash/funny3'

target = '/home/akash/funny3zip'

if not os.path.exists(target): 
    os.mkdir(target)
    
today = target + os.sep + time.strftime('%Y%m%d')

now = time.strftime('%H%M%S')

target = today+os.sep+now+'.zip'

if not os.path.exists(today): 
    os.mkdir(today)
    print('created today')
    
zip_command = "zip -r {0} {1}".format(target, ' '.join(source)) 
# Run the backup 
print ("Zip command is:")
print(zip_command)
print("Running:")
if os.system(zip_command) == 0:
    print('Successful backup to', target)
else:
    print('Backup FAILED')


# ## A simple class

# In[15]:


class Robot:
    
    # a class variable
    
    population = 0
    
    def __init__(self, name):
        # initialized the data
        self.name = name
        print("(Initializing {})".format(self.name))
        
        Robot.population += 1
        
    def die(self):
        # Dying
        
        print("{} is being destroyed".format(self.name))
        
        Robot.population -= 1
        
        if Robot.population == 0:
            print("{} was the last one".format(self.name))
        else:
            print("There are still {:d} robots working".format(Robot.population))
            
    def say_hi(self):
        # greeting
        
        print("Greetings, i am".format(self.name))
        
    @classmethod
    def how_many(cls):
        ## prints current population
        print(" we have {:d} robots. ". format(cls.population))


# In[16]:


droid1 = Robot("R2")
droid1.say_hi()
Robot.how_many()

droid2 = Robot("R3")
droid2.say_hi()
Robot.how_many()

print("they can work now")

print("destroyinnng...")

droid1.die()
droid2.die()

Robot.how_many()


# ## Inheritance

# In[42]:


class SchoolMember:
    def __init__(self, name, age):
        self.name = name
        self.age = age
        print('Initialized SchoolMember: {})'.format(self.name))
        
    def tell(self):
        '''Tell my details.''' 
        print('Name:"{}" Age:"{}"'.format(self.name, self.age))
        
        
class Teacher(SchoolMember):
    
    def __init__(self, name, age, salary):
        SchoolMember.__init__(self, name, age)
        self.salary = salary
        print('Initialized Teacher: {})'.format(self.name))
              
    def tell(self):
        SchoolMember.tell(self)
        print('Salary: "{:d}"'.format(self.salary))

class Student(SchoolMember):
    
    def __init__(self, name, age, marks):
        SchoolMember.__init__(self, name, age)
        self.marks = marks
        print('Initialized Student: {})'.format(self.name))
              
    def tell(self):
        
        SchoolMember.tell(self)
        print('Marks: "{:d}"'.format(self.marks)) 


# In[44]:


t = Teacher('A', 40, 20000)

s = Student('me', 25, 75)

m = [t, s]

for members in m:
    members.tell()


# ## Exceptions

# In[47]:


try:
    text = input("enter-->")
except EOFError:
    print('why eof')
else:
    print("you entered {}".format(text))


# ## Finally

# In[ ]:


import sys
import time 
f = None

try:
    f = open("poem.txt") # Our usual file-reading idiom 
    while True:
        line = f.readline()
        if len(line) == 0:
            break
        print line, sys.stdout.flush()
        print "Press ctrl+c now" # To make sure it runs for a while
        time.sleep(2) 
except IOError:
    print "Could not find file poem.txt" 
except KeyboardInterrupt:
    print "!! You cancelled the reading from the file."
finally: 
    if f: f.close()
        print "(Cleaning up: Closed the file)"


# ## With statement

# In[ ]:


with open('file.txt') as w:
    for line in w:
        print(line)


# ## Standard Libraries

# In[49]:


## sys module - system specific 

# print(sys.argv)


# In[50]:


sys.version_info


# In[ ]:


## Loggin module


import os, platform, logging

if platform.platform().startswith('Windows'):
    logging_file = os.path.join(os.getenv('HOMEDRIVE'), os.getenv('HOMEPATH'), 'test.log')
else: logging_file = os.path.join(os.getenv('HOME'), 'test.log')

print "Logging to", logging_file

logging.basicConfig( level=logging.DEBUG, format='%(asctime)s : %(levelname)s : %(message)s', filename = logging_file, filemode = 'w', )

logging.debug("Start of the program")
logging.info("Doing something")
logging.warning("Dying now")


# ## Lambda Forms

# In[51]:


points = [ { 'x' : 2, 'y' : 3 }, { 'x' : 4, 'y' : 1 } ]
points.sort(key=lambda i : i['y'])
print(points)


# ### List Comprehensions

# In[52]:


listone = [2, 3, 4]
listtwo = [2*i for i in listone if i > 2]
listtwo


# ## Assert

# In[53]:


mylist = ['item']
assert len(mylist) >= 1
mylist.pop()


# In[54]:


assert len(mylist) >= 1


# ### Decorators

# In[ ]:


from time import sleep
from functools import wraps
import logging
logging.basicConfig()
log = logging.getLogger("retry")


def retry(f):
    @wraps(f)
    def wrapped_f(*args, **kwargs):
        MAX_ATTEMPTS = 5
        for attempt in range(1, MAX_ATTEMPTS + 1):
            try:
                return f(*args, **kwargs)
            except:
                log.exception("Attempt %s/%s failed : %s", attempt, MAX_ATTEMPTS, (args, kwargs))
                sleep(10 * attempt)
            log.critical("All %s attempts failed : %s", MAX_ATTEMPTS, (args, kwargs))
        return wrapped_f
    counter = 0


    
@retry
def save_to_database(arg):
    print "Write to a database or make a network call or etc."
    print "This will be automatically retried if exception is thrown."
    global counter
    counter += 1 # This will throw an exception in the first call # And will work fine in the second call (i.e. a retry)
    if counter < 2:
        raise ValueError(arg)
    
if __name__ == '__main__':
    save_to_database("Some bad value")


# ### Command line arguments

# In[ ]:


#!/usr/bin/python

import sys

# it's easy to print this list of course:
print(sys.argv)

# or it can be iterated via a for loop:

for i in range(len(sys.argv)):
    if i == 0:
        print("Function name: %s" % sys.argv[0])
    else:
        print("%d. argument: %s" % (i,sys.argv[i]))


# In[ ]:


## OUTPUT 

$ python arguments.py arg1 arg2
['arguments.py', 'arg1', 'arg2']
Function name: arguments.py
1. argument: arg1
2. argument: arg2
$


# ### System programming and Python

# In[ ]:


## Packages:

os
platform
subprocess
shutils
glob
sys


# In[55]:


import os

print(os.name)


# These names define the following operating systems:
# 
# posix
# Unix-like operating systems like Unix, Linux, BSD, Minix and others.
# nt
# Windows systems like "Windows 10", "Windows 8.1", "Windows 8", "Windows 7" and so on.
# java
# Java operating system.

# In[ ]:


## Other common commands:

print(os.getcwd())
os.chdir("") ## Changes to the path mentioned
print(os.getcwd())

print(os.listdir()) ## names of the files of directory