Day 3: Data types and variables in python šŸ§”

aryan015 - Jul 17 - - Dev Community

You do not need to specify which data you assigning to variable. It is smartā›“ enough to recognize which datatype you are holding.
We will understand data type and variables hand to hand.

python variables

Variable in programming(in general) is nothing but a value that can be used multiple times in your code.

syntax

# syntax
# variable_name = data
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Look at below bad example

# take the user input name 
# and append welcome as a prefix
# bad apprach that might annoy user
print("welcome "+input("enter your name"))
print("bye "+input("enter your name"))
# use might save variable space (memory space) but it will be bad user experience
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Now example (good)

# good approach
# you might need username in future reference for the code so
name = input("enter your name")
print("welcome "+ name)
print("bye ")
# good approach
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Variable naming

  • use camleCasing
  • a variable name cannot start with a number. 9ty must be invalid.
  • Only special symbol allowed are underscore (_).

all below variable are valid

user_name = "aryan"
g8 = "aryan"
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supported datatypes [important]

I don't want to afraid you with hordes of data category.

# 1. string
# nothing but values between " and '
name = "aryan"
# 2. integer
# a number 
age = 26
PI = 3.14 # float
# 3. bool
# a value which either true or false
isQualify = True
canVote = False
# 4. list/array
# python array can hold multiple values (a container for different data)
fruits = ["apple","BananašŸŒ","mango"]
# 5. Dictionary
# a datatype that holds key value pair
# As of Python 3.7, dictionaries are ordered (items have a defined order).
# In Python 3.6 and earlier, dictionaries are unordered.
dict = {"brand": "Ford", "model": "Mustang", "year": 1964}
# 6. tuple
# an immutable datatype that contains any number of value and datatype and are ordered.
any_tuple = (1, "hello", 3.14, True, [10, 20])
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complete index
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