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Command Line Interface

Stable CLI options are stable in Levython 1.0.

The levython command is the main entry point for running Levython programs and accessing tools.

Table of Contents

Synopsis#

levython [options] [file] [arguments]

Running Programs#

Run a Levython file:

terminal 
# Run a .levy file
levython program.levy

# Run a .ly file (short extension)
levython program.ly

# Run from stdin
echo 'say("Hello!")' | levython -

# Run inline code
levython -e 'say("Hello!")'

Options#

Option Description
--version, -v Print version information
--help, -h Display help message
-e <code> Execute code from command line
- Read program from stdin
--debug Enable debug output
--ast Print parsed AST
--time Show execution time
terminal 
# Version
$ levython --version
Levython 1.0.0 (x86-64 JIT)

# Help
$ levython --help
Usage: levython [options] [file] [args...]

Options:
  --version, -v    Print version
  --help, -h       Show this message
  -e         Execute inline code
  --debug          Debug mode
  --ast            Print AST
  --time           Show timing info

# Time execution
$ levython --time fibonacci.levy
Result: 9227465
Execution time: 45ms

Package Manager#

Access the package manager through the CLI:

terminal 
# Install a package
levython lpm install math

# List installed packages
levython lpm list

# Remove a package
levython lpm remove math

# Or use the lpm command directly
lpm install math

See Package Manager (LPM) for complete documentation.

Examples#

Quick One-Liners

terminal 
# Print something
levython -e 'say("Hello, World!")'

# Do math
levython -e 'say(str(2 + 2))'

# Process piped input
echo "42" | levython -e 'say("Number: " + input())'

Running Tutorial Examples

terminal 
# Clone the repo
git clone https://github.com/levython/Levython.git
cd Levython

# Run examples
levython examples/01_hello_world.levy
levython examples/09_fibonacci.levy

Performance Benchmarking

terminal 
# Time the fibonacci benchmark
$ levython --time examples/09_fibonacci.levy
fib(35) = 9227465
Execution time: 45ms

# Compare with Python
$ time python3 -c "
def fib(n):
    return n if n <= 1 else fib(n-1) + fib(n-2)
print(fib(35))
"
# Output: ~2300ms