Das deutsche Python-Forum

Code: Alles auswählen

from pathlib import Path 
import json

SETTINGS_FILENAME = Path('dummy_f_dfg_ff__Y_TmP_mydata.json')

DEFAULTS = {
    'del_orphaned': False,   # if true:  del orphaned versions
    'demo_only': False,      # if true:  demo only
    'hide_versions': False,  # if true:  hide
    'symlinks_dirs': False,  # if false: ignore
    'symlinks_files': False, # if false: ignore
    # 'scan_all_subdirs', # visibility of subdirs for power-user
}


def read_settings():
    if not SETTINGS_FILENAME.exists():
        # read defaults
        return dict(DEFAULTS)
    else:
        # read from file
       return json.loads(SETTINGS_FILENAME.read_text())


def write_settings(data):
    SETTINGS_FILENAME.write_text(json.dumps(data))


def main():
    settings = read_settings()
    print(settings['demo_only'])
    settings['demo_only'] = True
    print(settings['demo_only'])
    write_settings(settings)

if __name__ == "__main__":
    main()

Code: Alles auswählen

def read_settings():
    try:
        contents = SETTINGS_FILE.read_text(encoding="utf-8")
    except FileNotFoundError:
        return dict(DEFAULTS)
    else:
        return json.loads(contents)

Code: Alles auswählen

import os
import json

# Meta-Bemerkungen (in deutscher Sprache) entfallen ab dem pre-release.
# Sie dienen bis dahin lediglich Kommentaren, welche zum leichteren Verständnis von "Merkwürdigkeiten" im Code dienen

# !access settings via this function only please!
def rw_settings(*args):
    """
    Read / write settings
    If no settings-file is found, use defaults
    
    *args:
      accepted are from 1 to 3 arguments

      args[0]:
        is defining the access-mode

        valid args[0]:
        - 'read_default_data'
          NO write operation is permitted

        - 'ro' (read only)
          return a dict-value
          EXCEPTION:
          in case no file for settings-data is found on disc,
          defaults initially are written to file
        
        - 'rw' (read write)
          case a, no (optional) third arg is available:
            return a value
          case b, a third arg is available:
            update a key-value and
            return this value
      
      args[1]:
        - represents a key only
      
      args[2]:
        - represents a value only
      
    Access samples:
    # sind hier noch veeeeeerkehrt angegeben .........................
    
    Read:
      rw_settings('ro', read_default_data')
      rw_settings('_symlinks_dirs')
    
    Write:
      rw_settings('_symlinks_dirs', 'True')
    """

    # no. of arguments: two or three only
    if 1 < len(args) > 3:
        
        # Implementation des error-handling ist temporär !!!

        print('!ERROR!   !ERROR!   !ERROR!')
        print('expected 1 or 2 args only, received:', len(args))
        quit()

    # Angabe des Arbeitsverzeichnisses und des Dateinamens ist temporär !!!
    # set path for settings-file
    data_path = '.\\dummy_f_dfg_ff__Y_TmP_mydata.json'

    # defaults for settings data
    data = {
        '_del_orphaned': False,   # if true:  del orphaned versions
        '_demo_only': False,      # if true:  demo only
        '_hide_versions': False,  # if true:  hide
        '_symlinks_dirs': False,  # if false: ignore
        '_symlinks_files': False, # if false: ignore
        # 'scan_all_subdirs', # visibility of subdirs for power-user
        }

    if args[0] == 'read_default_data':
        # return default dict
        return data

    elif args[0] == 'ro':
        # EXCEPTION:
        # in case no file is existing, create one, using default data
        if not os.path.exists(data_path):
            with open(data_path, 'w') as f:
               json.dump(data, f)

        # read settings from file
        with open(data_path, 'r') as f:
            data = json.load(f)

        return data[args[1]]

    elif args[0] == 'rw':
        # a third arg is expected
        # update key-value
        data[args[1]] = args[2]

        # write updated data to disc
        with open(data_path, 'w') as f:
           json.dump(data, f)

        return data[args[1]]

    else:
        print('!ERROR!   !ERROR!   !ERROR!')
        print('unknown arg received:', args[0])
        quit()

print("rw_settings('read_default_data'):")
print(rw_settings('read_default_data'))

print("rw_settings('ro', '_demo_only'):")
print(rw_settings('ro', '_demo_only'))

print("rw_settings('rw', '_demo_only', 'True'):")
print(rw_settings('rw', '_demo_only', 'True'))

Code: Alles auswählen

def write_settings(...

Code: Alles auswählen

def read_or_write_settings("write", ...