Of course! The command pyenv install python is the core of how pyenv works. However, it's not quite complete. You need to tell pyenv which specific version of Python you want to install.

Let's break down how to do it correctly, from installation to usage.

The Correct Command

The basic syntax is:

pyenv install <version>

For example, to install Python 3.11.4, you would run:

pyenv install 3.11.4

To install the latest stable Python 3.12, you could run:

pyenv install 3.12

Step-by-Step Guide to Installing Python with pyenv

Here is a complete walkthrough.

Step 1: Install Prerequisites

Before you can install Python, you need the necessary build tools and libraries on your system. This is the most common reason for installation failures.

On macOS (using Homebrew):

# Install Xcode Command Line Tools (includes compilers)
xcode-select --install
# Install pyenv dependencies
brew install openssl readline sqlite3 xz zlib

On Debian/Ubuntu:

# Update your package list
sudo apt update
# Install build dependencies
sudo apt install -y make build-essential libssl-dev zlib1g-dev \
libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm \
libncursesw5-dev xz-utils tk-dev libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev

On Fedora/CentOS/RHEL:

# Install development tools and required libraries
sudo dnf groupinstall "Development Tools"
sudo dnf install openssl-devel bzip2-devel libffi-devel-devel

Step 2: Install pyenv (If you haven't already)

If pyenv is not installed, follow the official instructions. The easiest way is using curl:

curl https://pyenv.run | bash

Then, you need to add pyenv to your shell's path. Add these lines to your shell profile file (~/.bashrc, ~/.zshrc, etc.):

export PYENV_ROOT="$HOME/.pyenv"
command -v pyenv >/dev/null || export PATH="$PYENV_ROOT/bin:$PATH"
eval "$(pyenv init -)"

After saving the file, restart your terminal or run source ~/.bashrc (or source ~/.zshrc) to apply the changes.

Step 3: Find Available Python Versions

You can't install a version you don't know about. List all available Python versions that pyenv can build.

pyenv install --list

This will give you a very long list. You can search through it using grep to find the version you want.

# Example: Find all 3.11 versions
pyenv install --list | grep " 3.11"

Step 4: Install the Python Version

Now, use the correct version number from the list.

# Example: Install a specific patch version
pyenv install 3.11.4
# Example: Install the latest 3.10 release
pyenv install 3.10

The installation will take a few minutes as it downloads the source code and compiles it on your machine.

Step 5: Set the Python Version for Your Project

This is the magic of pyenv. You can set different Python versions for different projects.

Option A: Set for the current directory (and its subdirectories)

This is the most common and recommended approach. pyenv will create a .python-version file in your current directory to remember your choice.

# Navigate into your project folder
cd /path/to/my/project
# Set the Python version for this project
pyenv local 3.11.4

Option B: Set the global Python version

This sets the default Python version for your user account on your system. It will be used in any directory where you haven't set a local version.

pyenv global 3.11.4

Step 6: Verify the Installation

Check which Python version is currently active.

python --version
# or
python3 --version

It should report the version you just set (e.g., Python 3.11.4).

You can also see the full path of the Python executable that pyenv is managing:

which python
# Should output something like: /home/your-user/.pyenv/versions/3.11.4/bin/python

Troubleshooting Common Issues

Issue 1: pyenv: install: command not found

This means pyenv is not in your system's PATH. Go back to Step 2 and make sure you've added the lines to your shell profile and restarted your terminal.

Issue 2: ERROR: The Python ssl extension was not compiled. Missing the OpenSSL lib?

This is a classic prerequisite issue. You likely missed Step 1. Go back and install the required libraries for your operating system (like libssl-dev on Ubuntu or openssl via Homebrew on macOS).

Issue 3: pyenv: no such version: ...

You made a typo in the version number. Run pyenv install --list to see the exact, available version strings and try again.

Issue 4: Installation is very slow

pyenv compiles Python from source code, which can be CPU-intensive and take several minutes. This is normal. If you have a multi-core processor, you can speed it up by telling the compiler to use more threads.

# Use all available cores
PYTHON_CONFIGURE_OPTS="--enable-optimizations" MAKE_OPTS="-j$(nproc)" pyenv install 3.11.4

(The nproc command on Linux gives the number of available cores. On macOS, you might use sysctl -n hw.ncpu instead.)