5 posts tagged with "Python"

I'll introduce commonly used code examples with graphs.

Table of Contents​

• Creating Graphs
  • Single Graph
  • 2 x 3 Graphs
• Plotting Graphs
• Setting Titles
• Setting Axis Labels
  • Setting X-Axis Labels
  • Setting Y-Axis Labels
• Setting Graph Top and Bottom
• Setting Graph Left and Right
• Displaying Grid
• Setting Ticks
• Removing Ticks
• Setting Tick Colors
• Adjusting Graph Spacing
• Saving Images

Creating Graphs​

First, import the required libraries.

import matplotlib.pyplot as plt
import numpy as np

Single Graph​

fig, ax = plt.subplots()

2 x 3 Graphs​

fig, axs = plt.subplots(2, 3)

Plotting Graphs​

Plotting a parabola

x = np.linspace(-1, 1, 201)
y = x ** 2

fig, ax = plt.subplots()
ax.plot(x, y)

Plotting a parabola with points

fig, ax = plt.subplots()

x = np.linspace(-1, 1, 21)
y = x ** 2

ax.plot(x, y, 'o')

Setting color to orange

fig, ax = plt.subplots()

x = np.linspace(-1, 1, 21)
y = x ** 2

ax.plot(x, y, color="tab:orange")

Standard colors are as follows:

Setting line width to 4

fig, ax = plt.subplots()

x = np.linspace(-1, 1, 21)
y = x ** 2

ax.plot(x, y, lw=4)

Setting Titles​

Setting title to "Title"

fig, ax = plt.subplots()
ax.set_title("Title")

Setting Axis Labels​

Setting X-Axis Labels​

Setting x-axis label to "Time (s)"

fig, ax = plt.subplots()
ax.set_xlabel("Time (s)")

Setting Y-Axis Labels​

Setting y-axis label to "Distance (m)"

fig, ax = plt.subplots()
ax.set_ylabel("Distance (m)")

Setting Graph Top and Bottom​

Setting top to 100

fig, ax = plt.subplots()
ax.set_ylim(top=100)

Setting bottom to -100

fig, ax = plt.subplots()
ax.set_ylim(bottom=-100)

Setting top to 100 and bottom to -100

fig, ax = plt.subplots()
ax.set_ylim([-100, 100])

Setting Graph Left and Right​

Setting left to -100

fig, ax = plt.subplots()
ax.set_xlim(left=-100)

Setting right to 100

fig, ax = plt.subplots()
ax.set_xlim(right=100)

Setting left to -100 and right to 100

fig, ax = plt.subplots()
ax.set_xlim([-100, 100])

Displaying Grid​

fig, ax = plt.subplots()
ax.grid()

Displaying grid vertically only

fig, ax = plt.subplots()
ax.grid(axis="x")

Displaying grid horizontally only

fig, ax = plt.subplots()
ax.grid(axis="y")

Setting Ticks​

Setting x-axis ticks

fig, ax = plt.subplots()
xticks = range(6)
ax.set_xticks(xticks)

Setting x-axis ticks and tick labels

fig, ax = plt.subplots()
xticks = range(6)
ax.set_xticks(xticks, [f"{xtick}m" for xtick in xticks])

Setting y-axis ticks

fig, ax = plt.subplots()
yticks = [i * 20 for i in range(6)]
ax.set_yticks(yticks)

Setting y-axis ticks and tick labels

fig, ax = plt.subplots()
yticks = [i * 20 for i in range(6)]
ax.set_yticks(yticks, [f"{ytick}%" for ytick in yticks])

Removing Ticks​

Removing x-axis ticks

fig, ax = plt.subplots()
ax.tick_params(bottom=False)

Removing x-axis tick labels

fig, ax = plt.subplots()
ax.tick_params(labelbottom=False)

Removing y-axis ticks

fig, ax = plt.subplots()
ax.tick_params(left=False)

Removing y-axis tick labels

fig, ax = plt.subplots()
ax.tick_params(labelleft=False)

Setting Tick Colors​

Setting x-axis tick color to red

fig, ax = plt.subplots()
ax.tick_params(axis="x", color="tab:red")

Setting x-axis tick label color to red

fig, ax = plt.subplots()
ax.tick_params(axis="x", labelcolor="tab:red")

Setting y-axis tick color to red

fig, ax = plt.subplots()
ax.tick_params(axis="y", color="tab:red")

Setting y-axis tick label color to red

fig, ax = plt.subplots()
ax.tick_params(axis="y", labelcolor="tab:red")

Adjusting Graph Spacing​

Setting vertical spacing to 0.2 and horizontal spacing to 0.3

fig, ax = plt.subplots(3, 3)
fig.subplots_adjust(hspace=0.2, wspace=0.3)

Setting spacing to automatic

fig, ax = plt.subplots(3, 3)
fig.tight_layout()

Saving Images​

Saving as PNG

fig, ax = plt.subplots()
plt.savefig("graph.png")

Saving as SVG

fig, ax = plt.subplots()
plt.savefig("graph.svg")

Saving as PDF

fig, ax = plt.subplots()
plt.savefig("graph.pdf")

graph.pdf

Saving at 300 dpi

fig, ax = plt.subplots()
plt.savefig("graph300.png", dpi=300)

Install Dependencies​

Reference: Home · pyenv/pyenv Wiki

sudo apt update
sudo apt install build-essential libssl-dev zlib1g-dev \
   libbz2-dev libreadline-dev libsqlite3-dev curl \
   libncursesw5-dev xz-utils tk-dev libxml2-dev libxmlsec1-dev libffi-dev lbmzma-dev

Install pyenv​

Reference: [pyenv/pyenv-installer: This tool is used to install pyenv and friends.] (https://github.com/pyenv/pyenv-installer?tab=readme-ov-file)

curl https://pyenv.run | bash

Add initialization script to ~/.bashrc​

# Open ~/.bashrc
code ~/.bashrc

Add the following:

export PYENV_ROOT="$HOME/.pyenv"
[[ -d $PYENV_ROOT/bin ]] && export PATH="$PYENV_ROOT/bin:$PATH"
eval "$(pyenv init -)"

eval "$(pyenv virtualenv-init -)"

Install Python​

Display a list of installable versions​

pyenv install -l

Install Python​

Install Python 3.12.2.

pyenv install 3.12.2

Set the Python version​

Set the default version to Python 3.12.2.

pyenv global 3.12.2

python -V # Python 3.12.2

Installing Poetry​

Install Poetry using pip. (It's also a good idea to upgrade pip at the same time.)

python -m pip install --upgrade pip
pip install poetry

Creating a Python Project with Poetry​

1. Creating a New Python Project​

To create a new Python project, run poetry new. A Python project template will be generated.

poetry new xxxxxxxx

2. Existing Python Project​

If you already have a Python project, run poetry init to add the necessary configuration files for Poetry.

poetry init

Entering the Poetry Virtual Environment​

Run poetry shell to start a shell in the Poetry virtual environment. You can use the packages added using Poetry.

poetry shell

Adding Packages to Poetry​

You can add dependency packages using poetry add.

poetry add xxxxxxxx

Other Commonly Used Commands​

• poetry list: Displays a list of commands.
• poetry build: Creates packages (.tar.gz, .whl).
• poetry install: Installs dependency packages.
• poetry publish: Publishes created packages to PyPI, etc.
• poetry search: Searches for packages.
• poetry run: Executes commands in the Poetry environment.
• poetry show: Displays available packages.
• poetry update: Executes dependency package updates.

Updating pip​

python -m pip install --upgrade pip

Installing with pip​

pip install jupyterlab

Launching​

jupyter lab --no-browser

0. Clone Pyenv Clone the Pyenv repository. The recommended directory is ~/ .pyenv.

git clone https://github.com/pyenv/pyenv ~/.pyenv

0. Compile Bash extensions for speed
   You can compile Bash extensions for speed.
   It will still work correctly if the compilation fails.

   ```sh
cd ~/.pyenv && src/configure && make -C src

0. Configuration (bash) Path and other settings.

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.profile echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.profile echo 'eval "$(pyenv init --path)"' >> ~/.profile export PYENV_ROOT="$HOME/.pyenv" export PATH="$PYENV_ROOT/bin:$PATH" eval "$(pyenv init --path)" echo -e 'if shopt -q login_shell; then'
'\n export PYENV_ROOT="$HOME/.pyenv"'
'\n export PATH="$PYENV_ROOT/bin:$PATH"'
'\n eval "$(pyenv init --path)"'
'\nfi' >> /.bashrc echo -e 'if [ -z "$BASH_VERSION" ]; then'
'\n export PYENV_ROOT="$HOME/.pyenv"'
'\n export PATH="$PYENV_ROOT/bin:$PATH"'
'\n eval "$(pyenv init --path)"'
'\nfi' >>/.profile

# Installing Python Environments

## Installing Dependencies
```sh
sudo apt-get update; sudo apt-get install make build-essential libssl-dev zlib1g-dev \
libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm \
libncurses-dev xz-utils tk-dev libxml2-dev libxmlsec1-dev libffi-dev liblemgma-dev -y

Checking Installable Environments​

pyenv install -l

Installing​

It takes a long time to compile, so please wait.

CONFIGURE_OPTS= "--enable-shared" pyenv install 3.9.5

Verifying Version​

pyenv versions

Switching Version​

pyenv global 3.9.5