Data types in python
- 3. Number data types store numeric values.
They are immutable data types, means that
changing the value of a number data type
results in a newly allocated object.
- 4. There are three numeric types to
present numbers-
Integer
Float
Complex
1
2
3
- 5. An integer is a whole number with no decimal
places. For example, 1 is an integer, but 1.0 isn’t.
The name for the integer data type is int.
Ex- type(1) <class 'int'>
- 6. A floating-point number, or float for short, is a
number with a decimal place. 1.0 is a floating-point
number, as is -2.75.
Ex- type(1.0) <class 'float'>
- 7. complex fare of the form a + bJ, where a and b are
floats and J (or j) represents the square root of -1
(which is an imaginary number). The real part of the
number is a, and the imaginary part is b. Complex
numbers are not used much in Python programming.
Ex- type(1+2j) <class 'float'>
- 8. The None keyword is used to define a null
value, or no value at all.
None is not the same as 0, False, or an
empty string. None is a data type of its own
(NoneType) and only None can be None.
- 9. x = None
if x:
print("Do you think None is True?")
elif x is False:
print ("Do you think None is False?")
else:
print("None is not True, or False, None is just None...")
Output-None is not True, or False, None is just None...
- 11. String are arrays of bytes representing Unicode
characters. A string is a collection of one or
more characters put in a single quote, double-
quote or triple quote. In python there is no
character data type, a character is a string of
length one. It is represented by str class.
- 12. To Access characters of String
String1 = “Python"
print("Initial String: ")
print(String1)
print("nFirst character of
String is: ")
print(String1[0])
Output-
Initial String:
Python
Output-
First character
of String is: P
- 13. A tuple is also a heterogeneous collection of
python objects seperated by commas .It means
object of different data types can consist of
tuple.
Ex- first_tuple=(2,3,4,6)
- 14. Python has two built-in methods that you can use on tuples.
Count()- Returns the number of times a specified value
occurs in a tuple.
Index()- Searches the tuple for a specified value and
retuns the position of where it was found.
- 15. It is a heterogeneous collection of items of varied
data types. For Ex, a list object can store files in a
folder or the employee data in a company etc.
Ex- List=[1,2,3,4]
O/P-List=[“Annu”, ”Mini”, 33, 44]
//Heterogeneous collection of items
- 17. A set is an unordered collection of unique and immutable
objects. Its definition starts with enclosed braces {} having
its items separated by commas inside.
Creating a set-
Set1={“BMW”, “Ferrari”, “Tesla”, “Ford”, ”Honda”}
Set2={Honda”,”Yamaha”,”Kawasaki”,20,40}
- 18. Union()- Return a set that contatins all items from both
sets, duplicates are excluded.
Intersection()- The intersection() method returns a set that
contains the similarity between two or more sets.
Difference()- Return the difference two sets which is also
a set.
Issubset()- The issubset() method returns True if all items
in the items in the set exists in the specidied set,
otherwise it return false.
- 19. A dictionary in Python is an unordered collection of key-value pairs.
Accessing values
Print(Dict1[Roll_No])
// output Dict1[Roll_No]) : 101
Print(Dict1[‘Name’])
// output Dict1[‘Name’]) : Kajal
Ex- Dict1= {
“Roll_No” : 101
“Name” : “Kajal”,
“Caste” : “Soni”,
“Class” : 12
}
- 20. Get()-Returns the value of the specified key.
Update()- Updates the dictionary with the specified key-vlaue
pairs.
Pop()- Removes the element with the specified key.
Copy()- Returns a copy of the dictionary.