Commit c00fe84a authored by Michele Maris's avatar Michele Maris
Browse files

u

parent efa2ddca

src/yapsut/__init__.py

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ from .ya_config import YA_CONFIG 
from .ya_hdr_parser import YA_HDR_PARSER

from .ya_extended_csv import ya_extended_csv

from .files import moveFile2backup

from .files import backup_open

from .wavenumber_base import wavenumber_base

from .profiling import timer,timerDict

from .struct import struct

src/yapsut/files.py

+68 −1
Original line number Diff line number Diff line 
def moveFile2backup(fname,skipTestExists=False) :

   """if exists creates a backup file for the file fname

      skipTestExists=True skips the test



      **deprecated** use `backup_open` instead

   """

   import time

   import os
@@ -8,3 +10,68 @@ def moveFile2backup(fname,skipTestExists=False) : 
   tt=fname+'.'+time.strftime('%y%m%dl%H%M%S',time.localtime())+'~'

   print('Existing '+fname+' -> ',tt)

   os.rename(fname,tt)



class backup_open:

   def __new__(cls, filename, mode='r', verbose=False, override=False, addtilde=False, policy='datetime', removebackup=False, *args, **kwargs):

      """ Acts as the starndard 'open' but if file is opened in writing ('w') and if the file already exists renames the old version to have a backup file

          mode = see `open` mode

          verbose      = print a message if renaming is done (False)

          policy       = policy for backup naming either: `bak`, `bak.number`, `number`, `datetime` (`datetime`)

          override     = does not create a backup but overrides the old file (False)

          removebackup = removes an existing backup file if present, to be used in `bak` policy (False)

      """

      import time

      import os

      tilde = '~' if addtilde else ''

      #

      # open without any test

      if override or not 'w' in mode:

         return open(filename, mode, *args, **kwargs)



      if os.path.exists(filename):

         if policy == 'bak' :

            backup_filename = f"{filename}.bak{tilde}"

         elif policy == 'bak.number' :

            n=0

            while True :

               backup_filename = f"{filename}.bak.{n}{tilde}"

               if not os.path.exists(backup_filename) or removebackup:

                  break

               n=n+1

         elif policy == 'number' :

            n=0

            while True :

               backup_filename = f"{filename}.{n}{tilde}"

               if not os.path.exists(backup_filename)  or removebackup:

                  break

               n=n+1

         elif policy == 'datetime' :

            n=0

            while True :

               pstfx=time.strftime('%y%m%dl%H%M%S',time.localtime())

               if n==0 :

                  backup_filename = f"{filename}.{pstfx}{tilde}"

               else :

                  backup_filename = f"{filename}.{pstfx}{n}{tilde}"

               if not os.path.exists(backup_filename) or removebackup:

                  break

               n=n+1

         else :

            raise Exception(f'policy "{policy}" is not a valid one, valid policies are "bak","number","bak.number","datetime","datetime.number"')



         # For cross-platform safety (especially Windows),

         # remove the old backup if it already exists before renaming

         if removebackup or policy == 'bak':

            if os.path.exists(backup_filename):

               os.remove(backup_filename)

               if verbose :

                  print(f"[Backup] already existing backup filename `{backup_filename}` removed")



         # rename the filename to backup

         os.rename(filename, backup_filename)

         if verbose :

            print(f"[Backup] Renamed existing '{filename}' to '{backup_filename}'")



      # Return a native file object using the built-in open()

      return open(filename, mode, *args, **kwargs)