Bar Chart in Plotly

Last Updated: 08 Nov 2025

---

Bar charts display categorical data with rectangular bars — perfect for comparisons, rankings, survey results, or sales by category.

Hinglish Tip: Bar chart = "kaun kitna hai" — jaise exam marks! Taller bar = zyada value.

---

Basic Bar Chart

import plotly.express as px

# Sample data
categories = ['Apple', 'Banana', 'Orange', 'Mango']
sales = [45, 30, 55, 40]

fig = px.bar(x=categories, y=sales, title="Fruit Sales")
fig.show()

---

Key Parameters in px.bar()

Parameter	Values / Examples	Purpose
data_frame	df	Use Pandas DataFrame
x, y	Column names	Categories & values
color	Column name	Color bars by group
barmode	'stack', 'group', 'overlay', 'relative'	How bars are placed
text	Column or 'auto'	Show values on bars
orientation	'v' (vertical), 'h' (horizontal)	Flip to horizontal bar
hover_data	['profit']	Extra info on hover
title	String	Chart title
labels	'y': 'Revenue'	Rename axes

---

Full Example: Grouped & Stacked Bar (Sales by Region)

import plotly.express as px
import pandas as pd

# Sample data
df = pd.DataFrame({
    'Month': ['Jan', 'Feb', 'Mar'] * 2,
    'Sales': [30, 35, 40, 25, 30, 38],
    'Region': ['North']*3 + ['South']*3,
    'Product': ['A', 'B', 'C'] * 2
})

# Grouped Bar
fig1 = px.bar(
    df, x='Month', y='Sales', color='Region',
    barmode='group',
    title='Sales by Region (Grouped)',
    labels={'Sales': 'Revenue (₹K)'},
    text='Sales',
    height=500
)
fig1.update_traces(textposition='outside')
fig1.show()

# Stacked Bar
fig2 = px.bar(
    df, x='Month', y='Sales', color='Region',
    barmode='stack',
    title='Sales by Region (Stacked)',
    text='Sales',
    hover_data=['Product']
)
fig2.update_traces(textposition='inside')
fig2.show()

Hinglish Tip: barmode='group' → side-by-side comparison, barmode='stack' → total dikhega + parts

---

Horizontal Bar Chart (orientation='h')

fig = px.bar(
    df, x='Sales', y='Product', color='Region',
    orientation='h',
    title='Top Products by Sales (Horizontal)',
    text='Sales',
    color_discrete_sequence=px.colors.qualitative.Set2
)
fig.update_traces(textposition='outside')
fig.show()

Hinglish Tip: Horizontal bar → long category names ke liye best (no overlap!)

---

Add Value Labels + Custom Colors

fig = px.bar(
    df, x='Month', y='Sales', color='Region',
    barmode='stack',
    text='Sales',
    color_discrete_map={'North': '#1f77b4', 'South': '#ff7f0e'}
)
fig.update_traces(texttemplate='%{text}K', textposition='inside')
fig.update_layout(uniformtext_minsize=10, uniformtext_mode='hide')
fig.show()

---

Common Mistakes to Avoid

Mistake	Fix
Text overlaps	Use textposition='outside' + uniformtext_mode
Too many colors → confusing	Use color_discrete_sequence=px.colors.qualitative.Pastel
Vertical labels unreadable	Use orientation='h'
Can't see small bars	Use barmode='stack' or log scale
No export	Install kaleido

---

---