Keywords

• The print function enables a Python program to display textual information to the user.

• Programs may use the input function to obtain information from the user.

• The simplest use of the input function assigns a string to a variable:

  • x = input()





• The parentheses are empty because, the input function does not require any information to do its job. Below program demonstrates that the input function produces a string value.

Shell Exercies

>>>x = input()
#enter text
'hi welcome to Ravula's Tutorials'
#prints value of variable x
>>>print(x)
hi welcome to Ravula's Tutorials

eval function

• The eval function dynamically translates the text provided by the user into an executable form that the program can process

• This allows users to provide input in a variety of flexible ways; for example, users can enter multiple entries separated by commas, and the eval function evaluates it as a Python tuple

  
  

>>>num1, num2 = eval(input('Please enter number 1, number 2: '))
>>>print(num1, '+', num2, '=', num1 + num2)

The following sample run shows how the user now must enter the two numbers at the same time separated by a comma:




Please enter number 1, number 2: 23, 10
23 + 10 = 33

Type Conversion in Python

• Casting is when you convert a variable value from one type to another
• In python this is done with functions such as int() or float() or str(). A very common pattern is that you convert a number, currently as a string into a proper number.



>>>x=input()
3
>>>print(type(x))
class 'str'

>>>x=int(input())
3
>>>print(type(x))
class 'int'

1. int(a,base) : This function converts any data type to integer. ‘Base’ specifies the base in which string is if data type is string.




# initializing string 
>>>s = "10010"
# printing string converting to int base 2
>>>c = int(s,2)
>>>print ("After converting to integer base 2 : ", end="") 
>>>print (c) 




After converting to integer base 2 : 18




2. float() : This function is used to convert any data type to a floating point number.




# initializing string 
>>>s = "10010"
# printing string converting to float 
>>>e = float(s)
>>>print ("After converting to float : ", end="")
>>>print (e) 




After converting to float : 10010.0




3. ord() : This function is used to convert a character to integer.




# initializing string 
>>>s = '4'
# printing character converting to integer 
>>c = ord(s)
>>>print ("After converting character to integer : ",end="") 
>>>print (c) 




After converting character to integer : 52




4. hex() : This function is to convert integer to hexadecimal string.




# initializing string 
>>>s = "4"
# printing integer converting to hexadecimal string
>>>c = hex(56)
>>>print ("After converting 56 to hexadecimal string : ",end="")  
>>>print (c) 




After converting 56 to hexadecimal string : 0x38




5. oct() : This function is to convert integer to octal string.




# initializing string 
>>>s = "10010"
# printing integer converting to octal string
>>>c = oct(56)
>>>print ("After converting 56 to octal string : ",end="")  
>>>print (c) 




After converting 56 to octal string : 0o70




6. tuple() : This function is used to convert to a tuple.




# initializing string 
>>>s = 'geeks'
# printing string converting to tuple
>>>c = tuple(s) )
>>>print ("After converting string to tuple : ",end="") 
>>>print (c) 




After converting string to tuple : ('g', 'e', 'e', 'k', 's')




7. set() : This function returns the type after converting to set.




# initializing string 
>>>s = 'geeks'
# printing string converting to set
>>>c = set(s) 
>>>print ("After converting string to set : ",end="") 
>>>print (c) 




After converting string to set : {'k', 'e', 's', 'g'}




8. list() : This function is used to convert any data type to a list type.




# initializing string 
>>>s = 'geeks'
# printing string converting to list
>>>c = list(s) 
>>>print ("After converting string to list : ",end="") 
>>>print (c) 




After converting string to list : ['g', 'e', 'e', 'k', 's']




9. dict() : This function is used to convert a tuple of order (key,value) into a dictionary.




# initializing integers  
>>>a,b=1,2
# initializing tuple
>>>tup = (('a', 1) ,('f', 2), ('g', 3))
# printing integer converting to complex number  
>>>c = complex(1,2)
>>>print ("After converting integer to complex number : ",end="") 
>>>print (c)  




After converting integer to complex number : (1+2j)




10. str() : Used to convert integer into a string.




# initializing integers  
>>>a,b=1,2
# initializing tuple
>>>tup = (('a', 1) ,('f', 2), ('g', 3))
# printing integer converting to string  
>>>c = str(a)
>>>print ("After converting integer to string : ",end="")  
>>>print (c)  




After converting integer to string : 1




11. complex(real,imag) : This function converts real numbers to complex(real,imag) number.




# initializing integers  
>>>a,b=1,2
# initializing tuple
>>>tup = (('a', 1) ,('f', 2), ('g', 3))
# printing tuple converting to expression dictionary  
>>>c = dict(tup) 
>>>print ("After converting tuple to dictionary : ",end="") 
>>>print (c)  




After converting tuple to dictionary : {'a': 1, 'f': 2, 'g': 3}