Generate files from templates

This code can be used to generate plain text files from templates.

Installing

To install the latest release from PyPI, run:

pip install qr-generate

To install the latest code from GitHub, run:

pip install git+https://github.com/quadraturerules/generate.git

Syntax

The following syntax can be used to generate text:

• For loops use the syntax {{for VARIABLE in LIST}} and {{end for}}
• Ifs use the syntax {{if CONDITION}} and {{end if}}

Examples

Looping in a file

To generate a file that prints each value in a list, the following template can be written:

template = """{{for v in values}}
print({{v}})
{{end for}}"""

A python script can then be used to generate the file:

import generate

t = generate.parse(template)
values = [
    generate.substitute.Float(i)
    for i in [1.0, 4.0, 6.0]
]
print(t.substitute(loop_targets={"values": values}))

The items in the list values passed in as a loop target must be a subclass of Substitutor.

Templating with a folder

Alternatively, you could create a folder called input_code and create a file inside it containing the file code.py with contents:

{{for v in values}}
print({{v}})
{{end for}}

and create a file in the directory called __gen__.py with contents:

import generate
loop_targets = {"values": [
    generate.substitute.Float(i)
    for i in [1.0, 4.0, 6.0]
]}

You can then run:

python -m generate input_code output_code

This would create a directory called output_code containing a file code.py with the template replacements having been made.

Generating multiple files from a .template file

When templating using a folder, a file for each entry in a list can be created by using a .template file. For example, if a file called p.template was added to the input_code directory with the contents

--
template: v in values
filename: p-{{v}}.py
--
print({{v}})

You can then run:

python -m generate input_code output_code

This would generate files called p-1.0.py, p-4.0py, and p-6.0.py.

Larger example

A larger example of the use of this library can be found by looking at the code used to generate the quadraturerules libraries associated with the online encylopedia of quadrature rules.