Merge pull request #48 from chrisjbillington/save-load-appconfig

Add `labconfig.{save,load}_appconfig()`

Author: chrisjbillington

labscript_utils/labconfig.py

@@ -10,9 +10,11 @@
 # for the full license.                                             #
 #                                                                   #
 #####################################################################
-import sys
 import os
 import configparser
+from ast import literal_eval
+from pprint import pformat
+from pathlib import Path
 
 from labscript_utils import dedent
 from labscript_profile import default_labconfig_path, LABSCRIPT_SUITE_PROFILE
@@ -69,3 +71,45 @@ def __init__(
                 not have the required keys. Make sure the config file containes the
                 following structure:\n{self.file_format}"""
             raise Exception(dedent(msg))
+
+
+def save_appconfig(filename, data):
+    """Save a dictionary as an ini file. The keys of the dictionary comprise the section
+    names, and the values must themselves be dictionaries for the names and values
+    within each section. All section values will be converted to strings with
+    pprint.pformat()."""
+    # Error checking
+    for section_name, section in data.items():
+        for name, value in section.items():
+            try:
+                valid = value == literal_eval(pformat(value))
+            except (ValueError, SyntaxError):
+                valid = False
+            if not valid:
+                msg = f"{section_name}/{name} value {value} not a Python built-in type"
+                raise TypeError(msg)
+    data = {
+        section_name: {name: pformat(value) for name, value in section.items()}
+        for section_name, section in data.items()
+    }
+    c = configparser.ConfigParser(interpolation=None)
+    c.optionxform = str # preserve case
+    c.read_dict(data)
+    Path(filename).parent.mkdir(parents=True, exist_ok=True)
+    with open(filename, 'w') as f:
+        c.write(f)
+
+
+def load_appconfig(filename):
+    """Load an .ini file and return a dictionary of its contents. All values will be
+    converted to Python objects with ast.literal_eval(). All keys will be lowercase
+    regardless of the written contents on the .ini file."""
+    c = configparser.ConfigParser(interpolation=None)
+    c.optionxform = str # preserve case
+    # No file? No config - don't crash.
+    if Path(filename).exists():
+        c.read(filename)
+    return {
+        section_name: {name: literal_eval(value) for name, value in section.items()}
+        for section_name, section in c.items()
+    }