Download Python Data Types: Understanding Numbers, Sequence Type, Boolean, Set, and Dictionary and more Cheat Sheet Mathematics in PDF only on Docsity!
Data Types in Python:
Python is a dynamically typed language; hence we do not need to define the type of the variable while declaring it. The interpreter implicitly binds the value with its type. a = 53 The variable a holds integer value and we did not define its type. Python interpreter will automatically interpret variables a as an integer type. Python enables us to check the type of the variable used in the program. Python provides us the type() function, which returns the type of the variable passed. a= 50 b="Hello Python" c = 50. print (type(a)) print (type(b)) print (type(c)) Python provides various standard data types that define the storage method on each of them. The data types defined in Python are given below.
- Numbers
- Sequence Type
- Boolean
- Set
- Dictionary
Numeric data type: Integer, Float, Complex
Sequence Type: Strings, List, Tuple
Numbers or Numeric Data Type:
Number stores numeric values. The integer, float, and complex values belong to a Python Numbers data-type. Python provides the type() function to know the data-type of the variable. Similarly, the isinstance() function is used to check an object belongs to a particular class.
Python creates Number objects when a number is assigned to a variable. For example; a = 52 print ("The type of a", type(a)) b = 4. print ("The type of b", type(b)) c = 10 +31j print ("The type of c", type(c)) print (" c is a complex number", isinstance( 10 +31j,complex)) Numeric data types:
- Int - Integer value can be any length such as integers 10, 2, 29, -20, - 150 etc. Python has no restriction on the length of an integer. Its value belongs to int
- Float - Float is used to store floating-point numbers like 1.9, 9.902, 15.2, etc. It is accurate upto 15 decimal points.
- complex - A complex number contains an ordered pair, i.e., x + iy where x and y denote the real and imaginary parts, respectively. The complex numbers like 2.14j, 2.0 + 2.3j, etc.
Sequence Type
String
The string can be defined as the sequence or collection of characters represented in the quotation marks. In Python, we can use single, double, or triple quotes to define a string. Types of strings in Python:
- Normal: “hello world” 2.Raw: A string prefixed with r or R is called a raw string. A 'raw string' is slightly different from a string where backslash \ , is just taken as a backslash, and not escape sequences to represent newlines, tabs, backspace, and so on.
print (list1[ 3 :])
List slicing
print (list1[ 0 : 2 ])
List Concatenation using + operator
print (list1 + list1)
List repetition using * operator
print (list1 * 3 ) Output: [1, 'hi', 'Python', 2] [2] [1, 'hi'] [1, 'hi', 'Python', 2, 1, 'hi', 'Python', 2] [1, 'hi', 'Python', 2, 1, 'hi', 'Python', 2, 1, 'hi', 'Python', 2]
Tuple
A tuple is similar to the list in many ways. Like lists, tuples also contain the collection of the items of different data types. The items of the tuple are separated with a comma (,) and enclosed in parentheses (). A tuple is a read-only data structure as we can't modify the size and value of the items of a tuple. Let's see a simple example of the tuple. tup = ("hi", "Python", 2 ) #Printing the tuple print (tup)
Tuple slicing
print (tup[ 1 :])
print (tup[ 0 : 1 ])
Tuple concatenation using + operator
print (tup + tup)
Tuple repetition using * operator
print (tup * 3 )
Adding value to tup. It will throw an error.
t[ 2 ] = "hi"
Dictionary
Dictionary is an unordered set of a key-value pair of items. It is like an associative array or a hash table where each key stores a specific value. Values in a dictionary can be of any data type and can be duplicated whereas keys cannot be repeated and must be immutable. Keys are case sensitive if two keys have same name but different cases, it will be treated distinctly. The items in the dictionary are separated with the comma (,) and enclosed in the curly braces {}. Consider the following example. d = { 1 :'Jimmy', 2 :'Alex', 3 :'john', 4 :'mike'}
Printing dictionary
print (d)
Accesing value using keys
print ("1st name is "+d[ 1 ]) print ("2nd name is "+ d[ 4 ]) print(d.get(3)) print (d.keys()) print (d.values()) Output:
set2.add( 10 ) print (set2) #Removing element from the set set2.remove( 2 ) print (set2) Output: {3, 'Python', 'James', 2} {'Python', 'James', 3, 2, 10} {'Python', 'James', 3, 10}
