Add some new helper methods to file utils.

[python_utils.git] / file_utils.py

diff --git a/file_utils.py b/file_utils.py
index 5d9a0be3b272bbc51eebf7894baac7a25fe11179..22210e4444afcb5223fbfcf70dcfe839baa15edd 100644 (file)
--- a/file_utils.py
+++ b/file_utils.py
@@ -9,6 +9,7 @@ import logging
 import os
 import io
 import pathlib
+import re
 import time
 from typing import Optional
 import glob
@@ -20,6 +21,34 @@ from uuid import uuid4
 logger = logging.getLogger(__name__)
 
 
+def remove_newlines(x):
+    return x.replace('\n', '')
+
+
+def strip_whitespace(x):
+    return x.strip()
+
+
+def remove_hash_comments(x):
+    return re.sub(r'#.*$', '', x)
+
+
+def read_file_to_list(
+    filename: str, *, skip_blank_lines=False, line_transformations=[]
+):
+    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_transformations:
+                line = transformation(line)
+            if skip_blank_lines and line == '':
+                continue
+            ret.append(line)
+    return ret
+
+
 def remove(path: str) -> None:
     """Deletes a file.  Raises if path refers to a directory or a file
     that doesn't exist.
@@ -184,6 +213,18 @@ def does_file_exist(filename: str) -> bool:
     return os.path.exists(filename) and os.path.isfile(filename)
 
 
+def file_is_readable(filename: str) -> bool:
+    return does_file_exist(filename) and os.access(filename, os.R_OK)
+
+
+def file_is_writable(filename: str) -> bool:
+    return does_file_exist(filename) and os.access(filename, os.W_OK)
+
+
+def file_is_executable(filename: str) -> bool:
+    return does_file_exist(filename) and os.access(filename, os.X_OK)
+
+
 def does_directory_exist(dirname: str) -> bool:
     """Returns True if a file exists and is a directory.