Python - Small Notes

• 1. Python allows you to change the datatype of a variable. int -> string -> float -> int

a = 1 # int  
a = "testing" # string

• 2. To prevent the datatype change in the future, apply "Type Hint" when defining a variable:

a: int
a = 1  # accepted

a = "testing" # Python will reject this assigning

• 3. Apply function Arrow to force the return datatype

def hello(name: str) -> str:
    return f"Hello {name}" # this only accept return a string.


def greeting(name: str) -> str:
    return True # this boolean will be rejected by Python 

It's different from other languages such as C#, Java, and Swift.

• Create a Python environment.

pip install pipenv
pipenv shell #create a new environment
pip i

OR

# create a new virtual environment
python3 -m venv .venv

#activate environment
source .venv/bin/activate