Data Types in Python

Data Types 

In C# or Java, You need to declare a variable specify them integer, string, and decimal. But in Python no need to specify. We can declare variables like

 
 Example: C# or Java

   int age = 28;
   string Name = "Siddhu";
   
 Example: Python

   age = 28
   Name = "Siddhu"

 

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So, you don't need to declare variable types in python. This is an advantage in Python, But still have few Disadvantages too.
Example: In my Python function

 
 def add_numbers(x,y):
  print(x+y)
    
  add_numbers(20,50)
  //Output: 70
   
  add_numbers(20,"Something")
  //Error:"Traceback (most recent call last):
   File "C:/Users/siddhartha.e/PycharmProjects/siddhu-py/my1stpycode.py", line 8, in 
   add_numbers(50,"Something")
   File "C:/Users/siddhartha.e/PycharmProjects/siddhu-py/my1stpycode.py", line 4, in add_numbers
   print(a + b)
   TypeError: unsupported operand type(s) for +: 'int' and 'str'"

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Python is not preventing you whether it is string or integer while you calling those functions, But in Python 3.5 we have a feature to add date types "type hinting" this will help you to guide while you writing code using IDE editors(it will show help text about variable type).

 Example: In my Python function(Type hinting)
 
  def add_numbers(x: int,y: int) -> int:
      return x + y
 

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                                                                 Demo

Integers and Floats

Defining integer and floats are very easy. You no need to bother about Postive value, Negative value or Decimal.

 
 age = 28
 Pi = 3.14159
 age + pi = 31.14159
 

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So, You don't need to worry about conversion.

Strings

We can use Strings to represent the text. The string can be defined by using Single quotes, Double quotes, and even Three quotes.

 
Example:
   'Hello World'
   "Hello World"
   """Hello World"""
    
   and all are eqaul same value 
   'Hello World' == "Hello World" == """Hello World"""
   
   Some of predefine functions
   print("siddhu".capitalize())
   //Output:Siddhu
   
   print("siddhu".replace("ddh","007"))
   //Output:si007u
   
   print("siddhu".isalpha())
   //Output:True
   
   print("siddhu007".isalpha())
   //Output:False
   
   print("siddhu".isdigit())
   //Output:False
   
   print("007".isdigit()) // useful converting to int
   //Output:True
   
   print("siddhu,james bond,Smith,Sachin".split(","))
   //Output:['siddhu', 'james bond', 'Smith', 'Sachin']

 

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String format functions

 
 Example:  name = "Siddhu"
   age = 28
   print("my name is {0} and age {1}".format(name,age))
   //Output:my name is Siddhu and age 28
    
   {0} is indicates the position of name and {1} as age of this Format() function. We can use {0} many times in the string.
   Seems good right. But How can you remember more arguments?. This 3.6 version brings an alternate solution.
    
   print( f"my name is {name} and age {age}" )
   //Output:my name is Siddhu and age 28
    
   Now you can directly use argument names instead of positions. But you have to prefix with "f" whole string.
 

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                                                                      Demo

Boolean and None

Boolean indicates TURE or FALSE values. Boolean most used in IF statements. You can convert a boolean value to an integer, The return statement "TRUE" consider as 1 and 0 consider as "FALSE".

 
 Example:     
     Ten_equals_ten = True
     Ten_equals_nine = False
     
     int(Ten_equals_ten) == 1
     int(Ten_equals_nine) == 0
     str(Ten_equals_nine) == "False"
     str(Ten_equals_ten) == "True"
 

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Coming to "None" value, that something you'll assign a value later but not now. For these cases, you can assign a variable value as "None".

 
 Example:   
     a = None
     print(a)
     //Output:None
     if you didn't assign "a" value as None then you will get below error if you use "a" value later.
                 NameError: name 's' is not defined
 

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                                                                        Demo