If L1 and L2 are list objects containing keys and respective values, following methods can be used to construct dictionary object. Zip two lists and convert to dictionary using dict() function >>> L1 = ['a','b','c','d'] >>> L2 = [1,2,3,4] >>> d = dict(zip(L1,L2)) >>> d {'a': 1, 'b': 2, 'c': 3, 'd': 4} Using dictionary comprehension syntax >>> L1 = ['a','b','c','d'] >>> L2 = [1,2,3,4] >>> d = {k:v for k,v in zip(L1,L2)} >>> d {'a': 1, 'b': 2, 'c': 3, 'd': 4}

If L1 and L2 are list objects containing keys and respective values, following list comprehension syntax can be used to construct dictionary object. >>> L1 = ['a','b','c','d'] >>> L2 = [1,2,3,4] >>> d = {L1[k]:L2[k] for k in range(len(L1))} >>> d {'a': 1, 'b': 2, 'c': 3, 'd': 4}

Dictionary object is an unordered collection of key-value pairs, separated by comma and enclosed in curly brackets. Association of value with key is marked by : symbol between them.>>> D1={'a':1,'b':2,'c':3}Key can appear in a dictionary object only once, whereas single value can be assigned to multiple keys. Key should be of immutable data type i.e. number, string or tuple.>>> D2={1:'aaa', 2:'bbb', 3:'ccc'} >>> D3={(10,10):'x1', (20,20):'x2'} >>> D4={'Microsoft':['MS Office', 'Windows', 'C#'], 'Oracle':['Oracle', 'Java', 'MySQL']}

Python’s number conversion function float() converts an integer to float with fractional part as 0. It also parses a string with valid representation of float number to a float object.>>> float('1.11') 1.11 >>> float(1) 1.0 >>> float('1') 1.0 >>> float('1.1e-2') 0.011

We have use oct() function from Python’s library to convert any integer to its octal equivalent number. We get a string having octal representation>>> oct(100) '0o144' >>> oct(0x10) '0o20' >>> oct(10) '0o12'

We can use built in hex() function to convert any integer to its hexadecimal representation.>>> hex(100) '0x64' >>> hex(4095) '0xfff' >>> hex(31) '0x1f'

ASCII character associated to an integer is obtained by chr() function. The argument for this function can be any number between 0 to 0xffff>>> chr(0xaa) 'ª' >>> chr(0xff) 'ÿ' >>> chr(200) 'È' >>> chr(122) 'z'

Python library's chr() function converts Unicode character associated to any integer which is between 0 an 0x10ffff.>>> chr(36) '$' >>> chr(97) 'a' >>> chr(81) 'Q'

Each character is associated with an ASCII value which is a unique number. It is obtained by ord() function.>>> ord('A') 65 >>> ord('+') 43 >>> ord(' ')

We can use zip() function to produce an iterable from two tuple objects, each corresponding to key and value items and then use dict() function to form dictionary object>>> T1=('a','b','c','d') >>> T2=(1,2,3,4) >>> dict((x,y) for x,y in zip(t1,t2))Dictionary comprehension syntax can also be used to construct dictionary object from two tuples>>> d={k:v for (k,v) in zip(T1,T2)} >>> d {'a': 1, 'b': 2, 'c': 3, 'd': 4}