python

print()

Displays output in the console so you can see what your code does

string (str)

A sequence of characters inside quotes like "Hello" or 'Python'

concatenation

Combining strings using the + operator

len()

Returns the length of an object

indexing

Accessing individual characters/items using their position

negative indexing

Accessing items from the end of a sequence using negative numbers

slicing

Extracting part of a sequence using start:stop format

variable

A named container that stores a value

=

Assigns a value to a variable

==

Checks whether two values are equal

int

A whole number data type like 5 or -3

float

A decimal number data type like 3.14

complex

A number containing real and imaginary parts like 2+3j

snake_case

Naming style using lowercase letters and underscores

f-string

A formatted string that inserts variables using curly brackets

.upper()

Converts a string to uppercase

.capitalize()

Makes the first letter uppercase

.replace()

Replaces characters or text inside a string

Boolean

A data type with only True or False values

comparison operators

Operators that compare values and return True or False

list

An ordered collection of items

list indexing

Accessing list items using their position

.append()

Adds an item to the end of a list

.remove()

Removes an item from a list

for loop

Repeats code for each item in a sequence

range()

Creates a sequence of numbers for loops

while loop

Repeats code while a condition remains True

dictionary

A collection of key-value pairs stored using curly brackets

key

The label used to access a dictionary value

value

The data stored inside a dictionary

dictionary access

Getting a value using dictionary["key"]

.items()

Returns dictionary keys and values together

.values()

Returns only dictionary values

pandas

A Python library used for data analysis and manipulation

import pandas as pd

Imports pandas and gives it the shortcut name pd

DataFrame

A table-like data structure with rows and columns

pd.read_csv()

Loads a CSV file into a DataFrame

df.head()

Shows the first rows of a DataFrame

df.tail()

Shows the last rows of a DataFrame

df.sample()

Shows random rows from a DataFrame

df["column"]

Selects a column from a DataFrame

df.loc[]

Selects rows and columns using labels

df.iloc[]

Selects rows and columns using positions

df.info()

Shows DataFrame structure and data types

df.describe()

Shows summary statistics

df.shape

Shows the number of rows and columns

aggregation

Calculating summary values like sum

min

max

or mean

groupby()

Groups data by categories for analysis

agg()

Applies multiple summary calculations at once

isnull()

Checks for missing values

dropna()

Removes rows or columns containing missing values

fillna()

Replaces missing values with a chosen value

replace()

Replaces incorrect or inconsistent values

sort_values()

Sorts a DataFrame by column values

merge()

Combines DataFrames using matching columns

inner join

Keeps only rows that exist in both DataFrames

left join

Keeps all rows from the left DataFrame and matching rows from the right

concat()

Combines DataFrames by stacking rows together

list comprehension

A short way to create or modify lists

zip()

Combines multiple lists into pairs

Plotly Express

A Python library used to create interactive visualizations

px.line()

Creates a line chart

px.scatter()

Creates a scatter plot

px.bar()

Creates a bar chart

px.histogram()

Creates a histogram

px.choropleth()

Creates a map visualizatio