Python Tutorial 0.0
Here we are with Python Tutotials ... We struggled to learn it and now we are okayish enough to write about it and help you guys learn . Starting the series of Python Tutorials, the introductory article in the series covers the basics that are "Must know" to go ahead in the journey.
So don't get scared of this, it's absolutely harmless !
Introduction to Spyder:
Let's now start learning the most basic coding of python
But before that few must know things about python:
1. Python is case sensitive in all respects. Here “a” and “A” are different objects.
2. Any statement starting with # is considered as non-executable comment, but it can not be of multiple line. For multiple line comment, use # in start of every line.
3. Ctrl + Enter command is used to execute a code in Script Editor window.
Assigning Values to Variables
A=10 # an integer assignment
Name="Hero" # a string assignment
No need of explicit declaration; The declaration happens automatically when you assign a value to a variable.
When a variable is assigned, it references to an object
# Want to know the value of the variable, simply write
A #and run execute command
or
print(A) #and run execute command
# Want to know the type of the variable
type(A)
# Want to get the list of currently defined variables
who
whos # for more details of the variables
# Want to delete the defined variable
del A # here A is a variable name
The data stored in Python can be of various types, lets learn some standard data types mentioned below:
- Numbers
- String
- List
- Tuple
- Dictionary
Numbers
var1= 2
var2= 9
# simple operation can be performed on number variables.
var3=var1+var2 # addition
var4=var2*var1 # multipilcation
var5=var2**var1 # exponential
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String
It is basically the text or set of characters represented in the quotation marks.
In string index is assigned to each character starting from 0 to n-1.
Slicing can be done using indexing method.
str = 'Hello friends, how r you'
# Do you want to get a first character of the string.
str[0]
Output : 'H'
# Do you want to get a range of characters
str[0:5]
Output : 'Hello'
# Backward indexing :
# if you want to get last characters
str[-1]
Output : 'u'
# Get last 3 character
str[-3:]
Output : 'you'
# Concatenation : How to add strings
# if you want to add strings
str + ', All'
Output : 'Hello friends, how r you, All'
# Repetition of strings
str *2
Output :'Hello friends, how r youHello friends, how r you'
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List
It is set of items(object) separated by commas and enclosed within square brackets ([ ]).
In list index is assigned to each item starting from 0 to n-1.
Slicing can be done using indexing method.
Item belonging to list can be of different data types.
Emp = [ 'Analyst', 60000, 'xyz', 4]
Note : List supports all the sequence operation same as string, shown above in the string section.
Emp[0] # Give you first element of the list
Emp[1:3] # Give you first and second element(n-1) of the list
Emp[-1] # Give you last element of the list
Emp + ['Delhi'] # Concatenate
There are few more operations which can be performed on the list. For example : sort, reverse, append etc. Lets understand by example.
lst=[1,5,2,7] # Defining a list of same data type
lst.append(10) # Output : [1, 5, 2, 7, 10]
lst.reverse() # Output : [10, 7, 2, 5, 1]
lst.sort() # Output : [1, 2, 5, 7, 10] sorting in ascending order
lst.sort(reverse=True) # Output : [10, 7, 5, 2, 1] sorting in descending order
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Tuple
Python tuple is similar to list with few differences, which are:
1. List is enclosed with [ ] and tuple is enclosed with ( ).
2. List can be updated but tuple can't.
Emp1 = [ 'Analyst', 60000, 'xyz', 4] # Defining List
type(Emp1) # Checking the type of Emp1
Emp2 = ( 'Senior Analyst', 80000, 'xyz', 6) # Defining Tuple
type(Emp2) # Checking the type of Emp2
Lets check the second difference.
Emp1[0]='Senior Analyst'
Emp2[0]='Manager'
Output: with error while updating tuple.
Dictionary
It is set of items(object) separated by commas and enclosed within curly brackets { }.
It is not sequence. Each element of the dictionary is not referenced by it relative position.
Each element is referenced by unique key.
It is set of "Key : Values" pairs.
Lets take an example of a dictionary.
Emp_d = {'Designation': 'Analyst', 'Monthly_Salary' :60000, 'Company':'xyz', 'Experience': 4}
type(Emp_d) # Output would be : dict
In above mentioned dictionary.
Keys are : Designation, Monthly_Salary, Company, Experience
Values are : Analyst, 60000, xyz, 4
We can get these values by code.
Emp_d.keys() # to get the keys
Emp_d.values() # to get the values
Emp_d['Designation'] # calling value by referring key
Emp_d['Department']='Sales' # adding one element with key : Department and Value : Sales
Enough for the first class !
Enjoy reading our other articles and stay tuned with us.
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