Boring Stuff With Python

This is a repository only for learning python and automate boring stuff in daily life.

You'll remember the things you do much better than the things you only read.

Expressions

2 + 2

Expressions consist of values (such as 2) and operators (such as +), and they can evaluate down to a single value.

Precedence

The ** operator is evaluated first; the *, /, //, and % are evaluted next, from left to right; and the + and - operators are evaluated last (also from left to right). You can use parentheses to override the usual precedence if you need to.

The Integer, Floating-Point, and String Data Types

A data type is a category for values, and every value belongs to exactly one data type.
The integer (or int) data type indicates values that are whole numbers.
Numbers with a decimal point, such as 3.14 are called floating point numbers (or floats).
Always surround your string in single quote (')
You can even have a string with no characters in it. '' called a blank string.

String Concatenation and Replication

+ is the addition operator when it operates on two integers or floating-point values. However, when + is used on two string values, it joins the strings as the string concatenation operator.
The * operator is used for multiplication when it operates on two integer or floating point values.But when the * operator is used on one string value and one integer value, it becomes the string replication operator.

Storing Values in Variables

A variable is like a box in the computer's memory where you can store a single value.
If you want to use the result of an evaluated expression later in your program, you can save it inside a variable.
Assignment Statements
- You'll store values in variables with an assignment statement. An assignment statement consists of a variable name, an equal sign (called the assignment operator), and the value to be stored.
- If you enter the assignment statement spam = 42, then a variable named spam will have the integer value 42 stored in it.

A Collection of Modules

Packages are nothing more than a folder of Python module files.
In the package folder, a file named init.py should be present,it can be empty
- This file can be used for package initialization
When Python sees this file, it treats the folder as a package, and it modules can be imported
The folder name is the package name, and can be thought of as a namespace

Publicly Distributed Packages

The Python Package Index is the official public package repository for Python.
The packages are simply shared code libraries which save developers lots of time by not requiring them to reinvent the wheel for each task they need to accomplish.
To use the repository to download and install packages, the program pip is used.
Pip is distributed with Python.
https://pypi.python.org/pypi

Installing Packages

Packages can be installed globally or for the user.
To install a package globally, open a terminal, and run the following command:
```
  pip install <package name>
```
To install the package for the current user only, run the following command:
```
  pip install --user <package name>
```

Removing Packages

To remove a package run:
```
  pip uninstall <package name>
```
If a package is installed locally (with --user) and globally, the local version will be installed first.
Run the command again to uninstall the package globally.

Listing Packages

To list all installed packages:
```
  pip list
```
To see a list of outdated packages:
```
  pip list --outdated
```
To upgrade a package:
```
  pip install --upgrade <package name>
```
To see more details of a package:
```
  pip show <package name>
```

Requirements File

To ensure packages are installed for a given application, a "requirements.txt" can be created.
To initially create the "requirements.txt" file, the pip "freeze" command can be used
```
  pip freeze > requirements.txt
```
The "requirements.txt" can be used by pip to install the packages listed inside of it
```
  pip install -r requirements.txt 
```

Aamir-Meman / BoringStuffWithPython