Before diving deep into the nitty-gritty details of a programming language or perhaps even a human language, we need
to understand its terminologies and basic principles and start building a basic mental model which we can come back and
refer whenever needed.
The building block of any programming language can be divided mainly into the following:
- Data Types
- Actions (functions)
- Best Practices
Today I spent understanding some basic Python terms, syntax, its data types and some of its actions or better known
as functions in programming terms.
Data Types in simple words are a way to represent values. In our physical world, we have letters, numbers, symbols as
different type of commonly used values. Similarly, Python comprises of these fundamental data types:
- int (to represent numbers)
- float (to represent decimal numbers)
- str (to represent strings)
- bool (to represent boolean)
- complex (not used very often)
- None (to represent an absence of value)
These are the standard data types available in Python. To create our own custom type, classes are used. Specialized data
types can also be used via importing external libraries or modules.
- number (for both whole and decimal numbers)
- undefined Also object as a non-primitive type.
Today I just spent time in understanding the number and string types of Python.
There are 3 types of numeric data types:
- int (stores whole numbers of unlimited size)
- float (stores floating-point real number values)
type function is used to determine the type of a value or an expression. (Similar to the
typeof operator in
num = 100 # variable assignement print(type(num)) # <class 'int'> num2 = 99.99 print(type(num2)) # <class 'float> expression1 = num * 10 print(type(expression1)) # <class 'int'> expression2 = num + num2 print(type(expression2)) # <class 'float'>
In Python, variable assignment happens by just writing a name and assigning a value using the
There are some built-in mathematical functions that allow us to calculate various mathematical operations with ease.
Math Functions and Constants - this document contains all the built-in
math functions and constants
print(round(2.1)) # 2 print(round(5.9)) # 6 print(abs(-34)) # 34
Will explore the math module in detail some other day.
Variables store values. In python, these are the variable naming conventions:
- Variables should start with a letter(preferrably lowercase) or underscore and can be followed by numbers or underscore
- Snake case is the conventional way of writing variable with multiple words such as
- They are case sensitive
- Keywords should not overwrite keywords (Python keywords)
name = 'Python' # string assignment within single quotes name2 = "Python" # string assingment within double quotes name3 = '''This is a a very long string and supports multiline statements as well''' # string assingment within 3 single quotes name4 = 'Hello! \"Rockstar Programmer\"' # string with escaped character sequence print(type(name)) # <class 'str'> print(type(name2)) # <class 'str'> print(type(name3)) # <class 'str'> print(type(name4)) # <class 'str'>
+ operator. It simply joins or 'concatenates' strings.
first_name = 'Mike' last_name = 'Tyson' print(first_name + ' ' + last_name) # Mike Tyson
operations are performed with different types
user_name = 'John' age = 40 print(user_name + age) # TypeError: can only concatenate str (not "int") to str # This would work in Javscript where it would convert the result to string type
In Python, types need to be converted explicitly to perform operations with different types
user_name = 'John' age = 40 print(user_name + str(age)) # John40 print(type str(age)) # <class 'str'>
Similarly, strings can be converted into numbers
lucky_number = 7 lucky_number_stringified = str(7) lucky_number_extracted = int(lucky_number_stringified) print(lucky_number_extracted) # 7
That's all for today! Still taking it simple and easy. Will continue understanding the other string operations and built-in methods and functions along
with Boolean and List types. Pretty excited for Day 3!
Have a great one!