Use pathlib

As pathlib.Path.__init__ accepts both a string and Path-like objects we can
stay backward compatible and still accept strings.

Also Two functions are deprecated since they don't provide much readability
over the pathlib implementation.

common_helper_files/__init__.py

-from .fail_safe_file_operations import (
-    get_binary_from_file, get_string_list_from_file, write_binary_to_file, get_safe_name, delete_file, get_files_in_dir,
-    get_dirs_in_dir, create_symlink, get_dir_of_file, safe_rglob
-)
-from .file_functions import read_in_chunks, get_directory_for_filename, create_dir_for_file, human_readable_file_size
+from .fail_safe_file_operations import (create_symlink, delete_file,
+                                        get_binary_from_file, get_dir_of_file,
+                                        get_dirs_in_dir, get_files_in_dir,
+                                        get_safe_name,
+                                        get_string_list_from_file, safe_rglob,
+                                        write_binary_to_file)
+from .file_functions import (create_dir_for_file, get_directory_for_filename,
+                             human_readable_file_size, read_in_chunks)
 from .git_functions import get_version_string_from_git
 
 __all__ = [

common_helper_files/fail_safe_file_operations.py

@@ -3,88 +3,73 @@ import os
 import re
 import sys
 from pathlib import Path
-from typing import Iterable
+from typing import Iterable, List, Union
 
 from .file_functions import create_dir_for_file
 
 
-def get_binary_from_file(file_path):
+def get_binary_from_file(file_path: Union[str, Path]) -> Union[str, bytes]:
     '''
     Fail-safe file read operation. Symbolic links are converted to text files including the link.
     Errors are logged. No exception raised.
 
     :param file_path: Path of the file. Can be absolute or relative to the current directory.
-    :type file_path: str
     :return: file's binary as bytes; returns empty byte string on error
     '''
     try:
-        if os.path.islink(file_path):
-            binary = 'symbolic link -> {}'.format(os.readlink(file_path))
+        p = Path(file_path)
+        if p.is_symlink():
+            # We need to wait for python 3.9 for Path.readlink
+            binary = f'symbolic link -> {os.readlink(p)}'
         else:
-            with open(file_path, 'rb') as f:
-                binary = f.read()
+            binary = p.read_bytes()
     except Exception as e:
-        logging.error('Could not read file: {} {}'.format(sys.exc_info()[0].__name__, e))
+        logging.error(f'Could not read file: {sys.exc_info()[0].__name__} {e}')
         binary = b''
+
     return binary
 
 
-def get_string_list_from_file(file_path):
+def get_string_list_from_file(file_path: Union[str, Path]) -> List[str]:
     '''
     Fail-safe file read operation returning a list of text strings.
     Errors are logged. No exception raised.
 
     :param file_path: Path of the file. Can be absolute or relative to the current directory.
-    :type file_path: str
     :return: file's content as text string list; returns empty list on error
     '''
-    try:
-        raw = get_binary_from_file(file_path)
-        raw_string = raw.decode(encoding='utf-8', errors='replace')
-        cleaned_string = _rm_cr(raw_string)
-        return cleaned_string.split('\n')
-    except Exception as e:
-        logging.error('Could not read file: {} {}'.format(sys.exc_info()[0].__name__, e))
-        return []
+    raw = get_binary_from_file(file_path)
+    raw_string = raw.decode(encoding='utf-8', errors='replace')
+    cleaned_string = _rm_cr(raw_string)
+    return cleaned_string.split('\n')
 
 
 def _rm_cr(input_string):
     return input_string.replace('\r', '')
 
 
-def write_binary_to_file(file_binary, file_path, overwrite=False, file_copy=False):
+def write_binary_to_file(file_binary: Union[str, bytes], file_path: Union[str, Path], overwrite: bool = False, file_copy: bool = False) -> None:
     '''
     Fail-safe file write operation. Creates directories if needed.
     Errors are logged. No exception raised.
 
     :param file_binary: binary to write into the file
-    :type file_binary: bytes or str
-    :param file_path: Path of the file. Can be absolute or relative to the current directory.
-    :type file_path: str
+    :param file_path_str: Path of the file. Can be absolute or relative to the current directory.
     :param overwrite: overwrite file if it exists
-    :type overwrite: bool
     :default overwrite: False
     :param file_copy: If overwrite is false and file already exists, write into new file and add a counter to the file name.
-    :type file_copy: bool
     :default file_copy: False
-    :return: None
     '''
     try:
+        file_path = Path(file_path)
         create_dir_for_file(file_path)
-        if not os.path.exists(file_path) or overwrite:
-            _write_file(file_path, file_binary)
-        elif file_copy and not overwrite:
-            new_path = _get_counted_file_path(file_path)
-            _write_file(new_path, file_binary)
+        if file_path.exists() and (not overwrite or file_copy):
+            file_path = Path(_get_counted_file_path(str(file_path)))
+        file_path.write_bytes(file_binary)
     except Exception as e:
         logging.error('Could not write file: {} {}'.format(sys.exc_info()[0].__name__, e))
 
 
-def _write_file(file_path, binary):
-    with open(file_path, 'wb') as f:
-        f.write(binary)
-
-
 def _get_counted_file_path(original_path):
     tmp = re.search(r'-([0-9]+)\Z', original_path)
     if tmp is not None:
@@ -95,55 +80,46 @@ def _get_counted_file_path(original_path):
     return new_file_path
 
 
-def delete_file(file_path):
+def delete_file(file_path: Union[str, Path]) -> None:
     '''
     Fail-safe delete file operation. Deletes a file if it exists.
     Errors are logged. No exception raised.
 
     :param file_path: Path of the file. Can be absolute or relative to the current directory.
-    :type file_path: str
-    :return: None
     '''
     try:
-        os.unlink(file_path)
+        Path(file_path).unlink()
     except Exception as e:
         logging.error('Could not delete file: {} {}'.format(sys.exc_info()[0].__name__, e))
 
 
-def create_symlink(src_path, dst_path):
+def create_symlink(src_path: Union[str, Path], dst_path: Union[str, Path]) -> None:
     '''
     Fail-safe symlink operation. Symlinks a file if dest does not exist.
     Errors are logged. No exception raised.
 
     :param src_path: src file
-    :type src_path: str
     :param dst_path: link location
-    :type dst_path: str
-    :return: None
     '''
     try:
         create_dir_for_file(dst_path)
-        os.symlink(src_path, dst_path)
+        Path(dst_path).symlink_to(src_path)
     except FileExistsError as e:
         logging.debug('Could not create Link: File exists: {}'.format(e))
     except Exception as e:
         logging.error('Could not create link: {} {}'.format(sys.exc_info()[0].__name__, e))
 
 
-def get_safe_name(file_name, max_size=200, valid_characters='abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_+. '):
+def get_safe_name(file_name: str, max_size: int = 200, valid_characters: str = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_+. ') -> str:
     '''
     removes all problematic characters from a file name
     cuts file names if they are too long
 
     :param file_name: Original file name
-    :type file_name: str
     :param max_size: maximum allowed file name length
-    :type max_size: int
     :default max_size: 200
     :param valid_characters: characters that shall be allowed in a file name
-    :type valid_characters: str
     :default valid_characters: 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_+. '
-    :return: str
     '''
     allowed_charachters = set(valid_characters)
     safe_name = filter(lambda x: x in allowed_charachters, file_name)
@@ -154,54 +130,49 @@ def get_safe_name(file_name, max_size=200, valid_characters='abcdefghijklmnopqrs
     return safe_name
 
 
-def get_files_in_dir(directory_path):
+def get_files_in_dir(directory_path: Union[str, Path]) -> List[str]:
     '''
     Returns a list with the absolute paths of all files in the directory directory_path
 
     :param directory_path: directory including files
-    :type directory_path: str
-    :return: list
     '''
     result = []
     try:
         for file_path, _, files in os.walk(directory_path):
             for file_ in files:
-                result.append(os.path.abspath(os.path.join(file_path, file_)))
+                result.append(str(Path(file_path, file_).absolute()))
     except Exception as e:
         logging.error('Could not get files: {} {}'.format(sys.exc_info()[0].__name__, e))
     return result
 
 
-def get_dirs_in_dir(directory_path):
+def get_dirs_in_dir(directory_path: Union[str, Path]) -> List[str]:
     '''
     Returns a list with the absolute paths of all 1st level sub-directories in the directory directory_path.
 
     :param directory_path: directory including sub-directories
-    :type directory_path: str
-    :return: list
     '''
     result = []
     try:
-        dir_content = os.listdir(directory_path)
-        for item in dir_content:
-            dir_path = os.path.join(directory_path, item)
-            if os.path.isdir(dir_path):
-                result.append(dir_path)
+        p = Path(directory_path)
+        for item in p.iterdir():
+            if not Path(item).is_dir():
+                continue
+            result.append(str(item.resolve()))
     except Exception as e:
         logging.error('Could not get directories: {} {}'.format(sys.exc_info()[0].__name__, e))
+
     return result
 
 
-def get_dir_of_file(file_path):
+def get_dir_of_file(file_path: Union[str, Path]) -> str:
     '''
     Returns absolute path of the directory including file
 
     :param file_path: Path of the file
-    :type: path-like object
-    :return: string
     '''
     try:
-        return os.path.dirname(os.path.abspath(file_path))
+        return str(Path(file_path).resolve().parent)
     except Exception as e:
         logging.error('Could not get directory path: {} {}'.format(sys.exc_info()[0].__name__, e))
         return '/'

common_helper_files/file_functions.py

-import os
+import io
+from pathlib import Path
+from typing import Type, Union
+
 import bitmath
 
 
-def read_in_chunks(file_object, chunk_size=1024):
+def read_in_chunks(file_object: Type[io.BufferedReader], chunk_size=1024) -> bytes:
     '''
     Helper function to read large file objects iteratively in smaller chunks. Can be used like this::
 
@@ -12,7 +15,6 @@ def read_in_chunks(file_object, chunk_size=1024):
 
     :param file_object: The file object from which the chunk data is read. Must be a subclass of ``io.BufferedReader``.
     :param chunk_size: Number of bytes to read per chunk.
-    :type chunk_size: int
     :return: Returns a generator to iterate over all chunks, see above for usage.
     '''
     while True:
@@ -22,35 +24,36 @@ def read_in_chunks(file_object, chunk_size=1024):
         yield data
 
 
-def get_directory_for_filename(filename):
+def get_directory_for_filename(filename: Union[str, Path]) -> str:
     '''
     Convenience function which returns the absolute path to the directory that contains the given file name.
 
     :param filename: Path of the file. Can be absolute or relative to the current directory.
-    :type filename: str
     :return: Absolute path of the directory
+
+    .. deprecated::
+        You should use pathlib instead of this function.
+
     '''
-    return os.path.dirname(os.path.abspath(filename))
+    return str(Path(filename).resolve().parent)
 
 
-def create_dir_for_file(file_path):
+def create_dir_for_file(file_path: Union[str, Path]) -> None:
     '''
     Creates all directories of file path. File path may include the file as well.
 
     :param file_path: Path of the file. Can be absolute or relative to the current directory.
-    :type file_path: str
-    :return: None
+
+    .. deprecated::
+        You should use pathlib instead of this function.
     '''
-    directory = os.path.dirname(os.path.abspath(file_path))
-    os.makedirs(directory, exist_ok=True)
+    Path(file_path).resolve().parent.mkdir(parents=True, exist_ok=True)
 
 
-def human_readable_file_size(size_in_bytes):
+def human_readable_file_size(size_in_bytes: int) -> None:
     '''
     Returns a nicly human readable file size
 
     :param size_in_bytes: Size in Bytes
-    :type size_in_bytes: int
-    :return: str
     '''
     return bitmath.Byte(bytes=size_in_bytes).best_prefix().format('{value:.2f} {unit}')

common_helper_files/git_functions.py

 import subprocess
 
 
-def get_version_string_from_git(directory_name):
+def get_version_string_from_git(directory_name: str) -> str:
     return subprocess.check_output(['git', 'describe', '--always'], cwd=directory_name).strip().decode('utf-8')