Python has various standard data types that are used to define the operations possible on them and the storage method for each of them.
Python supports four different numerical types -
int − They are often called just integers or ints, are positive or negative whole numbers with no decimal point.
long − Also known as longs, they are infinite-sized integers written as integers and followed by an uppercase or lowercase L.
float − Also called floats, they represent real numbers and are written with a decimal point dividing the integer and fractional parts. Floats may also be in scientific notation, with E or e indicating the power of 10 (2.5e2 = 2.5 x 102 = 250).
complex − These are complex numbers of the form a bJ , where a and b are floating point numbers and J (or j) represents the square root of -1 (that is, an imaginary number). The real part of the number is a and the imaginary part is b. In Python programming, complex numbers are rarely used.
Let us see an example −
# Python int val1 = 25 print(val1) # Python float val2 = 11.89 print(val2) # Python complex val3 = 6+2.9j print(val3) # Python hexadecimal val4 = 0x12d print(val4) # Python octal val5 = 0o021 print(val5)
25 11.89 (6+2.9j) 301 17
The Boolean type has two values, True and False. True represents 1, False represents 0. Let's see an example -
a = (1 == True) b = (1 == False) print(a) print(b)
True False
We can easily create a string by enclosing the characters in quotes. Python treats single quotes as synonyms for double quotes. Creating a string is as simple as assigning a value to a variable.
Let’s see how to easily create a String in Python −
myStr = Thisisit!'
We will now see an example of creating single and multi-line strings −
str1 = "John" print(str1) # Multi-line string str2 = """ This, is it! """ print(str2)
John This, is it!
A list contains items separated by commas and enclosed within square brackets ([]). Creating a list is as simple as putting different comma-separated values between square brackets. A list can have integer, string or float elements. With that , we can also create a List with mixed data types.
The list can be written as a list of comma-separated values (items) between square brackets. Important thing about a list is that the items in a list need not be of the same type
We will create a list with 10 integer elements and display it. The elements are enclosed by square brackets. With that, we have also displayed the length of the list and how we can access specific elements using the square brackets −
The Chinese translation of# Create a list with integer elements mylist = [25, 40, 55, 60, 75, 90, 105, 130, 155, 180]; # Display the list print("List = ",mylist) # Display the length of the list print("Length of the List = ",len(mylist)) # Fetch 1st element print("1st element = ",mylist[0]) # Fetch last element print("Last element = ",mylist[-1])
List = [25, 40, 55, 60, 75, 90, 105, 130, 155, 180] Length of the List = 10 1st element = 25 Last element = 180
We can also add string elements to Python lists. We will create a list of 5 string elements and display it. Elements are enclosed in square brackets. By doing this we also show the length of the list and how to access the first and last element using square brackets −
The Chinese translation of# Create a list with string elements mylist = ["BMW","Audi","Tesla","Honda","Toyota"]; # Display the list print("List = ",mylist) # Display the length of the list print("Length of the List = ",len(mylist)) # Fetch 1st element print("1st element = ",mylist[0]) # Fetch last element print("Last element = ",mylist[-1])
List = ['BMW', 'Audi', 'Tesla', 'Honda', 'Toyota'] Length of the List = 5 1st element = BMW Last element = Toyota
A tuple is a series of immutable Python objects. Tuples and lists are sequences. The main difference between tuples and lists is that tuples are immutable while lists are mutable. Tuples use parentheses, while lists use square brackets.
Let us first create a basic Tuple with integer elements and then move towards Tuples within a Tuple −
The Chinese translation of# Creating a Tuple mytuple = (20, 40, 60, 80, 100) # Displaying the Tuple print("Tuple = ",mytuple) # Length of the Tuple print("Tuple Length= ",len(mytuple))
Tuple = (20, 40, 60, 80, 100) Tuple Length= 5
Python's dictionary is a hash table type. They work like associative arrays or hashes in Perl, consisting of key-value pairs. The correct syntax for creating a Python dictionary is to store values in the form of key:value pairs. The left side of the colon stores the key, and the right side stores the value, that is,
key:value
Dictionary is enclosed by curly bracket and do not allow duplicates. According to the 3.7 Python update, dictionaries are now ordered. Consider Dictionary as a set of key: value pairs, with the requirement that the keys are unique (within one dictionary). Each key in a Dictionary is separated from its value by a colon (:), the items are separated by commas, and the whole thing is enclosed in curly braces.
We will create 4 key-value pairs, with keys Product, Model, Units and Available and values Mobile, XUT, 120 and Yes. Keys are on the left of colon, whereas values are on the right −
# Creating a Dictionary with 4 key-value pairs myprod = { "Product":"Mobile", "Model": "XUT", "Units": 120, "Available": "Yes" } # Displaying the Dictionary print("Dictionary = \n",myprod)
Dictionary = {'Product': 'Mobile', 'Model': 'XUT', 'Units': 120, 'Available': 'Yes'}
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