"""Utilities for working with files."""
+import contextlib
import datetime
import errno
import glob
import hashlib
-import io
import logging
import os
import pathlib
import re
import time
from os.path import exists, isfile, join
-from typing import List, Optional, TextIO
+from typing import Callable, List, Literal, Optional, TextIO
from uuid import uuid4
logger = logging.getLogger(__name__)
-def remove_newlines(x):
+def remove_newlines(x: str) -> str:
return x.replace('\n', '')
-def strip_whitespace(x):
+def strip_whitespace(x: str) -> str:
return x.strip()
-def remove_hash_comments(x):
+def remove_hash_comments(x: str) -> str:
return re.sub(r'#.*$', '', x)
filename: str,
*,
skip_blank_lines=False,
- line_transformers=[],
+ line_transformers: Optional[List[Callable[[str], str]]] = None,
):
ret = []
if not file_is_readable(filename):
raise Exception(f'{filename} can\'t be read.')
with open(filename) as rf:
for line in rf:
- for transformation in line_transformers:
- line = transformation(line)
+ if line_transformers is not None:
+ for transformation in line_transformers:
+ line = transformation(line)
if skip_blank_lines and line == '':
continue
ret.append(line)
>>> os.path.exists(path)
True
"""
- logger.debug(f"Creating path {path}")
+ logger.debug("Creating path %s", path)
previous_umask = os.umask(0)
try:
os.makedirs(path)
os.utime(filename, None)
-def convert_file_timestamp_to_datetime(
- filename: str, producer
-) -> Optional[datetime.datetime]:
+def convert_file_timestamp_to_datetime(filename: str, producer) -> Optional[datetime.datetime]:
ts = producer(filename)
if ts is not None:
return datetime.datetime.fromtimestamp(ts)
return get_file_timestamp_age_seconds(filename, lambda x: x.st_mtime)
-def get_file_timestamp_timedelta(
- filename: str, extractor
-) -> Optional[datetime.timedelta]:
+def get_file_timestamp_timedelta(filename: str, extractor) -> Optional[datetime.timedelta]:
age = get_file_timestamp_age_seconds(filename, extractor)
if age is not None:
return datetime.timedelta(seconds=float(age))
yield file_or_directory
-class FileWriter(object):
+class FileWriter(contextlib.AbstractContextManager):
+ """A helper that writes a file to a temporary location and then moves
+ it atomically to its ultimate destination on close.
+
+ """
+
def __init__(self, filename: str) -> None:
self.filename = filename
uuid = uuid4()
self.handle = open(self.tempfile, mode="w")
return self.handle
- def __exit__(self, exc_type, exc_val, exc_tb) -> Optional[bool]:
+ def __exit__(self, exc_type, exc_val, exc_tb) -> Literal[False]:
if self.handle is not None:
self.handle.close()
cmd = f'/bin/mv -f {self.tempfile} {self.filename}'
ret = os.system(cmd)
if (ret >> 8) != 0:
- raise Exception(f'{cmd} failed, exit value {ret>>8}')
- return None
+ raise Exception(f'{cmd} failed, exit value {ret>>8}!')
+ return False
if __name__ == '__main__':