"""
This module contains data structures required to create and access files. Users will generally only need to use
DataFile directly. LogFile and ErrorFile are used indirectly by the BCP classes.
Example:
.. code-block:: python
from bcp import DataFile
# create a csv to write out my data
my_file = DataFile(delimiter=',')
print(my_file.path) # %HOME%/bcp/data/<timestamp>.csv
"""
import abc
import datetime
from pathlib import Path
from .config import BCP_LOGGING_DIR, BCP_DATA_DIR
[docs]class File(abc.ABC):
"""
This data structure creates a file handle given a file path.
If the file path is not provided:
- the current timestamp is used so that unique error, log, and data files can be created
- the file will be created in the BCP_ROOT_DIR directory specified in config.py
"""
_default_extension = None
_default_directory = None
_file = None
@property
def file(self) -> Path:
return self._file
@file.setter
def file(self, value: Path = None):
"""
This method generates a default file path object if none is provided
Returns:
a Path object that points to the file
"""
if value is not None:
self._file = value
else:
timestamp_format: str = '%Y_%m_%d_%H_%M_%S_%f'
timestamp = datetime.datetime.now()
file_name: str = '.'.join([timestamp.strftime(timestamp_format), self._default_extension])
self._file = self._default_directory / Path(file_name)
@property
def path(self) -> Path:
return self.file.absolute()
[docs]class DataFile(File):
"""
This is a handle to a data file.
Args:
file_path: the path object to the file, if not provided, a default using the current timestamp will be created
delimiter: the field delimiter for the data file
"""
def __init__(self, file_path: Path = None, delimiter: str = None):
self._default_directory = BCP_DATA_DIR
self.delimiter = delimiter or '\t'
if self.delimiter == '\t':
self._default_extension = 'tsv'
elif self.delimiter == ',':
self._default_extension = 'csv'
else:
self._default_extension = 'dat'
self.file = file_path
[docs]class LogFile(File):
"""
This is a handle to a log file.
Args:
file_path: the path object to the file, if not provided, a default using the current timestamp will be created
"""
def __init__(self, file_path: Path = None):
self._default_directory = BCP_LOGGING_DIR
self._default_extension = 'log'
self.file = file_path
[docs]class ErrorFile(File):
"""
This is a handle to an error file.
Args:
file_path: the path object to the file, if not provided, a default using the current timestamp will be created
"""
def __init__(self, file_path: Path = None):
self._default_directory = BCP_DATA_DIR
self._default_extension = 'err'
self.file = file_path