A trend Graph is a graph that is used to show the trends data over a period of time.

It describes a functional representation of two variables $($x $,$ y$).$

In which the x is the time$-$dependent variable whereas y is the collected data.

The graph can be in shown any form that can be via line chart, Histograms, scatter plot, bar chart, and pie$-$chart.

In python, we can plot these trend graphs by using matplotlib.pyplot library.

It is used for plotting a figure for the given data.

Python Practice $1->$

# import all the libraries

import numpy as np

import pandas as pd

import matplotlib.pyplot as plt

# Create a dataframe

data $=\{$

"medals": $[100,92,102,56,78,56,78,96],$

"Time$\_$Period": $[2010,2011,2012,2013,2014,2015,2016,2017]$

$\}$

df $=$ pd$.$DataFrame$($data$)$

print$($df$)$

# to plot the graph

df$.$plot$($x$=$"Time$\_$Period", y$=$"medals", kind$=$"line"$)$

plt$.$show$()$

Python Practice $2->$ the following is Python code to plot a scatter plot and a bar graph using the provided data:

# Scatter plot

plt$.$figure$($figsize$=(8,6))$

plt$.$scatter$($df$[\text{'}$Time$\_$Period'$],$ df$[\text{'}$medals$\text{'}],$ color$=$'blue'$)$

plt$.$title$(\text{'}$Scatter Plot of Medals Over Time Period'$)$

plt$.$xlabel$(\text{'}$Time Period'$)$

plt$.$ylabel$(\text{'}$Medals$\text{'})$

plt$.$grid$($True$)$

plt$.$show$()$

# Bar graph

plt$.$figure$($figsize$=(8,6))$

plt$.$bar$($df$[\text{'}$Time$\_$Period'$],$ df$[\text{'}$medals$\text{'}],$ color$=$'green'$)$

plt$.$title$(\text{'}$Bar Graph of Medals Over Time Period'$)$

plt$.$xlabel$(\text{'}$Time Period'$)$

plt$.$ylabel$(\text{'}$Medals$\text{'})$

plt$.$grid$($True$)$

plt$.$show$()$

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$[$QUESTION TO ANSWER$]->$ Practice $3$: student getting marks in $2010.$

Consider the above Practice $1$ and Practice $2$ steps, we require a line graph showing $2$ trends based on:

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$$ Marks achieved in $2010$ by subject.

$$ Based on $2$ groups score: Semester $1$ and Semester $2.$