1+ '''
2+ Created on Aug 7, 2017
3+
4+ @author: Aditya
5+
6+ This program demonstrates the CONTAINERS in python
7+ '''
8+
9+ def func_tuple ():
10+ print ('Demo of Tuples in python.' )
11+ print ('NOTE: Tuple is immutable object.' )
12+
13+ t = 1 ,2 ,3 ,4 # comma separated list gives a tuple in python
14+ print ('NOTE: Comma separation results in tuple not the paranthesis.' )
15+ print ('Tuple: ' ,t )
16+
17+ print ('First tuple element:' ,t [0 ])
18+ print ('Last tuple element:' ,t [- 1 ])
19+ print ('Length of Tuple:' ,len (t ))
20+ print ('Minimum:' ,min (t ))
21+ print ('Maximum:' ,max (t ))
22+ print ('Tuple with only one element:' , (1 ,))
23+ print ((1 ,),':' ,type ((1 ,)))
24+
25+ t = tuple (range (25 ))
26+ print ('tuple t:' ,t )
27+ print (type (t ))
28+ print ('Check for presence of 10 in\' t\' :' , (10 in t ))
29+ print ('Check for presence of 50 in\' t\' :' , (50 in t ))
30+ print ('Check for absence of 50 in\' t\' :' , (50 not in t ))
31+
32+ print ('Count Number of 5s in t:' ,t .count (5 ))
33+ print ('Index of 5 and 6 in t:' ,t .index (5 ))
34+
35+
36+ def func_list ():
37+ print ('Demo for LISTs in python.' )
38+ print ('Note: Lists are mutable objects' )
39+ print ('Created using square brackets.' )
40+
41+ l = [1 ,2 ,3 ,4 ,5 ,6 ,5 ]
42+ print ('List:' ,l )
43+ print ('First element:' ,l [0 ])
44+ print ('Last element:' ,l [- 1 ])
45+ print ('Length:' ,len (l ))
46+ print ('Max:' ,max (l ))
47+ print ('Min:' ,min (l ))
48+ print ('List using list constructor:' ,list (range (10 )))
49+ print ('Count 5s in l:' ,l .count (5 ))
50+ print ('Index of 5 in l:' ,l .index (5 ))
51+ print ('Appending 1000 at the end of list l:' )
52+ l .append (1000 )
53+ print (l )
54+
55+ print ('Add multiple objects at end of list.' )
56+ l .extend (range (20 ))
57+ print (l )
58+
59+ print ('Insert 300 at the begining of l:' )
60+ l .insert (0 ,300 )
61+ print (l )
62+
63+ print ('Remove 300 from l:' )
64+ l .remove (300 )
65+ print (l )
66+
67+ print ('Delete item at index 10 from l:' )
68+ del l [10 ]
69+ print (l )
70+
71+ print ('Remove and return that removed value from end of the list l:' )
72+ a = l .pop ()
73+ print ('Popped element of l:' ,a )
74+ print ('l:' ,l )
75+
76+ print ('Pop from index 0:' )
77+ a = l .pop (0 )
78+ print ('Popped element:' ,a )
79+ print ('l:' ,l )
80+
81+
82+ def func_dictionaries ():
83+ print ('Dictionaries are python version of associative arrays or hash arrays.' )
84+ d = {'one' :2 ,'two' :2 ,'three' :3 ,'four' :4 ,'human' :'me' }
85+ x = dict (animal = 'dog' ,god = 'almighty' ,hero = 'batman' )
86+ print ('d-> {}' .format (d ))
87+ print ('x-> {}' .format (x ))
88+
89+ print ('Combine two dictionaries:' )
90+ a = {** d ,** x }
91+ print ('Combined Dictionaries:' ,a )
92+
93+ print ('Check for\' four\' in a:' , ('four' in a ))
94+ print ('Check for absence of\' alpha\' in a:' , ('alpha' not in a ))
95+
96+ for k ,v in a .items ():print (k ,v ,end = '|' )
97+
98+ print ('Use get method of dictionary to get a value for key and not the key-index because key-index with throw exception.' )
99+ print ('While get method gives\' None\' .' )
100+ try :
101+ print (a ['Morrow' ])
102+ except Exception as e :
103+ print ('Exception thrown as {}' .format (e ))
104+
105+ print ('Not present shown in NONE type:' ,a .get ('Morrow' ))
106+
107+ print ('Setting different default:' ,a .get ('Morrow' ,'Not present in dictionary' ))
108+
109+ print ('Popping a value from p:' )
110+ b = a .pop ('god' )
111+ print (a )
112+ print ('popped value ->' ,b )
113+
114+ def byte_n_byte_array ():
115+ print ('Bytes and Bytesarray contain bytes and not any other objects like in lists and tuples.' )
116+ print ('1byte = 8 bits' )
117+ print ('1byte = 256 different values' )
118+ print ('bytearray - mutable list of bytes.' )
119+ print ('Note: ord(\' char\' ) gives the integer equivalent of that character.' )
120+ print ('Normal ASCII range: 0 to 127' )
121+
122+ print ('Open file sample.txt for reading(\' r\' ) and with encoding as utf_8 and ignore the default encoding.' )
123+ file_in = open ('sample.txt' ,'r' ,encoding = 'utf_8' )# open input file
124+
125+ file_out = open ('sample.html' ,'w' )# opening output file to write('w')
126+
127+ outbytes = bytearray ()# initialize the byte array
128+
129+ for line in file_in :# iterate through the file
130+ for c in line :# iterate through each character of the line
131+ if ord (c )> 127 :# check if the integer equivalent of the character is out of normal ascii range
132+ outbytes += bytes ('&#{:04d};' .format (ord (c )),encoding = 'utf_8' )# append bytes to bytearray container using (+=) operator and formating as utf_8
133+ else :outbytes .append (ord (c ))# if character is with the normal ascii range append as it is to bytearray container
134+
135+ outstring = str (outbytes ,encoding = 'utf_8' )# output as string from bytearray
136+ print (outstring ,file = file_out )# print the output string to the output file file_out(sample.html)
137+ print (outstring )
138+
139+ print ('Yo!!' )
140+
141+ def main ():
142+ func_tuple ()
143+ print ()
144+ func_list ()
145+ print ()
146+ func_dictionaries ()
147+ print ()
148+ byte_n_byte_array ()
149+
150+ if __name__ == '__main__' :main ()