https://github.com/braincore/code-writer
A Python 3 library with convenience functions for generating code in any language.
https://github.com/braincore/code-writer
code-generation
Last synced: 5 months ago
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A Python 3 library with convenience functions for generating code in any language.
- Host: GitHub
- URL: https://github.com/braincore/code-writer
- Owner: braincore
- License: mit
- Created: 2019-03-03T12:04:27.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2025-12-23T01:30:01.000Z (5 months ago)
- Last Synced: 2025-12-24T15:20:26.965Z (5 months ago)
- Topics: code-generation
- Language: Python
- Size: 20.5 KB
- Stars: 5
- Watchers: 3
- Forks: 1
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE-MIT
Awesome Lists containing this project
README
# Code Writer [![Latest Version]][PyPI] [![Build Status]][Travis]
[Latest Version]: https://img.shields.io/pypi/v/code-writer.svg
[PyPI]: https://pypi.org/project/code-writer/
[Build Status]: https://api.travis-ci.com/braincore/code-writer.svg?branch=master
[Travis]: https://travis-ci.com/braincore/code-writer
A Python 3 library with convenience functions for generating code in any
language.
Based on the code generation backend in
[Stone](http://www.github.com/dropbox/stone) that's used to generate code in
many languages: C#, Java, Python, Ruby, Rust, Typescript, and more.
# Why?
You know all of the pains with code generation (coding, build process,
maintenance), but have decided you have no other choice. This library makes
generating code a little bit more manageable.
# Alternatives
If your code generation needs are simple, consider using a template language
such as [Jinja2](https://github.com/pallets/jinja).
# Install
```bash
pip3 install code-writer
```
# Usage
## Basics
You'll need to import `CodeWriter`:
```python
from code_writer import CodeWriter
```
## Examples
You probably want to write the output of `render()` to a file, but for
illustrative purposes we'll print them.
### Hello, world.
```python
cw = CodeWriter()
cw.emit('hello,')
with cw.indent():
cw.emit('world.')
print(cw.render())
```
Output:
```
hello,
world.
```
### Python if statement
```python
cw = CodeWriter()
cw.emit('if True:')
with cw.indent():
cw.emit('print("hello, world.")')
print(cw.render())
```
Output:
```python
if True:
print("hello, world.")
```
### Rust if statement
Use `block()` to create an indented block enclosed by curly braces.
```python
cw = CodeWriter()
with cw.block(before='if true', delim=('{', '}')):
cw.emit('println!("hello, world.");')
print(cw.render())
```
Output:
```rust
if true {
println!("hello, world.");
}
```
You can also set a default delimiter:
```python
cw = CodeWriter(default_delim=('{', '}'))
```
### Tabs
```python
cw = CodeWriter(use_tabs=True)
```
### Indent two spaces
```python
cw = CodeWriter(default_dent=2)
```
### Generate lists
```python
cw = CodeWriter()
cw.emit_list([], ('[', ']'), before='let li1 = ', after=';')
cw.emit_list(['1'], ('[', ']'), before='let li2 = ', after=';')
cw.emit_list(['1', '2', '3'], ('[', ']'), before='let li3 = ', after=';')
cw.emit_list(['1', '2', '3'], ('[', ']'), before='let li4 = ', after=';', compact=True)
print(cw.render())
```
Output:
```rust
let li1 = [];
let li2 = [1];
let li3 = [
1,
2,
3,
];
let li4 = [1,
2,
3];
```
### Generate wrapped text
This is useful for documentation.
```python
# Artificially set col width low to show wrapped text
cw = CodeWriter(default_width=25)
cw.emit('/**')
cw.emit_wrapped_text(
'@param param1 an explanation of what this argument does.',
prefix=' * ',
indent_after_first=True,
)
cw.emit('*/')
print(cw.render())
```
Output:
```java
/**
* @param param1 an
* explanation of
* what this argument
* does.
*/
```
### Emit a preamble or header
```python
preamble = """\
This
is
a
preamble.
"""
cw = CodeWriter()
cw.emit_raw(preamble)
print(cw.render())
```
Output:
```
This
is
a
preamble.
```
### Trim trailing newlines
Sometimes you'll want a newline after every iteration of logic, but not for the
last iteration.
```python
cw = CodeWriter()
with cw.block(before='if true', delim=('{', '}')):
for i in range(3):
cw.emit('println!("{}");'.format(i))
cw.emit()
print(cw.render())
```
Output:
```rust
if true {
println!("0");
println!("1");
println!("2");
}
```
The gap after the last `println!()` is undesirable. To fix, do this:
```python
cw = CodeWriter()
with cw.block(before='if true', delim=('{', '}')):
for i in range(3):
cw.emit('println!("{}");'.format(i))
cw.emit()
cw.trim_last_line_if_empty()
print(cw.render())
```
Output:
```rust
if true {
println!("0");
println!("1");
println!("2");
}
```
### Naming conventions
Depending on your target language, you may need to output names that are
PascalCase, camelCase, underscore_delimited, or dash-delimited.
```python
from code_writer import fmt_camel, fmt_dashes, fmt_pascal, fmt_underscores
# The input name can be a mix of formatting. These helpers will aggressively
# split the word and re-assemble as desired.
text = 'a-B-HiHo-merryOh_yes_no_XYZ'
assert fmt_camel(text) == 'aBHiHoMerryOhYesNoXyz'
assert fmt_dashes(text) == 'a-b-hi-ho-merry-oh-yes-no-xyz'
assert fmt_pascal(text) == 'ABHiHoMerryOhYesNoXyz'
assert fmt_underscores(text) == 'a_b_hi_ho_merry_oh_yes_no_xyz'
```