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dupeguru/hscommon/util.py
2013-06-22 21:32:23 -04:00

351 lines
11 KiB
Python

# Created By: Virgil Dupras
# Created On: 2011-01-11
# Copyright 2013 Hardcoded Software (http://www.hardcoded.net)
#
# This software is licensed under the "BSD" License as described in the "LICENSE" file,
# which should be included with this package. The terms are also available at
# http://www.hardcoded.net/licenses/bsd_license
import sys
import os
import os.path as op
import re
from math import ceil
import glob
import shutil
from . import io
from .path import Path
def nonone(value, replace_value):
''' Returns value if value is not None. Returns replace_value otherwise.
'''
if value is None:
return replace_value
else:
return value
def tryint(value, default=0):
try:
return int(value)
except (TypeError, ValueError):
return default
def minmax(value, min_value, max_value):
"""Returns `value` or one of the min/max bounds if `value` is not between them.
"""
return min(max(value, min_value), max_value)
#--- Sequence related
def dedupe(iterable):
'''Returns a list of elements in iterable with all dupes removed.
'''
result = []
seen = {}
for item in iterable:
if item in seen:
continue
seen[item] = 1
result.append(item)
return result
def flatten(iterables, start_with=None):
'''Takes a list of lists 'lists' and returns a list containing elements of every list.
If start_with is not None, the result will start with start_with items, exactly as if
start_with would be the first item of lists.
'''
result = []
if start_with:
result.extend(start_with)
for iterable in iterables:
result.extend(iterable)
return result
def first(iterable):
"""Returns the first item of 'iterable'
"""
try:
return next(iter(iterable))
except StopIteration:
return None
def stripfalse(seq):
"""Returns a sequence with all false elements stripped out of seq.
"""
return [x for x in seq if x]
def extract(predicate, iterable):
"""Separates the wheat from the shaft (`predicate` defines what's the wheat), and returns both.
"""
wheat = []
shaft = []
for item in iterable:
if predicate(item):
wheat.append(item)
else:
shaft.append(item)
return wheat, shaft
def allsame(iterable):
"""Returns whether all elements of 'iterable' are the same.
"""
it = iter(iterable)
try:
first_item = next(it)
except StopIteration:
raise ValueError("iterable cannot be empty")
return all(element == first_item for element in it)
def trailiter(iterable, skipfirst=False):
"""Yields (prev_element, element), starting with (None, first_element).
If skipfirst is True, there will be no (None, item1) element and we'll start
directly with (item1, item2).
"""
it = iter(iterable)
if skipfirst:
prev = next(it)
else:
prev = None
for item in it:
yield prev, item
prev = item
#--- String related
def escape(s, to_escape, escape_with='\\'):
return ''.join((escape_with + c if c in to_escape else c) for c in s)
def get_file_ext(filename):
"""Returns the lowercase extension part of filename, without the dot."""
pos = filename.rfind('.')
if pos > -1:
return filename[pos + 1:].lower()
else:
return ''
def rem_file_ext(filename):
"""Returns the filename without extension."""
pos = filename.rfind('.')
if pos > -1:
return filename[:pos]
else:
return filename
def pluralize(number, word, decimals=0, plural_word=None):
"""Returns a string with number in front of s, and adds a 's' to s if number > 1
number: The number to go in front of s
word: The word to go after number
decimals: The number of digits after the dot
plural_word: If the plural rule for word is more complex than adding a 's', specify a plural
"""
number = round(number, decimals)
format = "%%1.%df %%s" % decimals
if number > 1:
if plural_word is None:
word += 's'
else:
word = plural_word
return format % (number, word)
def format_time(seconds, with_hours=True):
"""Transforms seconds in a hh:mm:ss string.
If `with_hours` if false, the format is mm:ss.
"""
minus = seconds < 0
if minus:
seconds *= -1
m, s = divmod(seconds, 60)
if with_hours:
h, m = divmod(m, 60)
r = '%02d:%02d:%02d' % (h, m, s)
else:
r = '%02d:%02d' % (m,s)
if minus:
return '-' + r
else:
return r
def format_time_decimal(seconds):
"""Transforms seconds in a strings like '3.4 minutes'"""
minus = seconds < 0
if minus:
seconds *= -1
if seconds < 60:
r = pluralize(seconds, 'second', 1)
elif seconds < 3600:
r = pluralize(seconds / 60.0, 'minute', 1)
elif seconds < 86400:
r = pluralize(seconds / 3600.0, 'hour', 1)
else:
r = pluralize(seconds / 86400.0, 'day', 1)
if minus:
return '-' + r
else:
return r
SIZE_DESC = ('B','KB','MB','GB','TB','PB','EB','ZB','YB')
SIZE_VALS = tuple(1024 ** i for i in range(1,9))
def format_size(size, decimal=0, forcepower=-1, showdesc=True):
"""Transform a byte count in a formatted string (KB, MB etc..).
size is the number of bytes to format.
decimal is the number digits after the dot.
forcepower is the desired suffix. 0 is B, 1 is KB, 2 is MB etc.. if kept at -1, the suffix will
be automatically chosen (so the resulting number is always below 1024).
if showdesc is True, the suffix will be shown after the number.
"""
if forcepower < 0:
i = 0
while size >= SIZE_VALS[i]:
i += 1
else:
i = forcepower
if i > 0:
div = SIZE_VALS[i-1]
else:
div = 1
format = '%%%d.%df' % (decimal,decimal)
negative = size < 0
divided_size = ((0.0 + abs(size)) / div)
if decimal == 0:
divided_size = ceil(divided_size)
else:
divided_size = ceil(divided_size * (10 ** decimal)) / (10 ** decimal)
if negative:
divided_size *= -1
result = format % divided_size
if showdesc:
result += ' ' + SIZE_DESC[i]
return result
_valid_xml_range = '\x09\x0A\x0D\x20-\uD7FF\uE000-\uFFFD'
if sys.maxunicode > 0x10000:
_valid_xml_range += '%s-%s' % (chr(0x10000), chr(min(sys.maxunicode, 0x10FFFF)))
RE_INVALID_XML_SUB = re.compile('[^%s]' % _valid_xml_range, re.U).sub
def remove_invalid_xml(s, replace_with=' '):
return RE_INVALID_XML_SUB(replace_with, s)
def multi_replace(s, replace_from, replace_to=''):
"""A function like str.replace() with multiple replacements.
replace_from is a list of things you want to replace. Ex: ['a','bc','d']
replace_to is a list of what you want to replace to.
If replace_to is a list and has the same length as replace_from, replace_from
items will be translated to corresponding replace_to. A replace_to list must
have the same length as replace_from
If replace_to is a basestring, all replace_from occurence will be replaced
by that string.
replace_from can also be a str. If it is, every char in it will be translated
as if replace_from would be a list of chars. If replace_to is a str and has
the same length as replace_from, it will be transformed into a list.
"""
if isinstance(replace_to, str) and (len(replace_from) != len(replace_to)):
replace_to = [replace_to for r in replace_from]
if len(replace_from) != len(replace_to):
raise ValueError('len(replace_from) must be equal to len(replace_to)')
replace = list(zip(replace_from, replace_to))
for r_from, r_to in [r for r in replace if r[0] in s]:
s = s.replace(r_from, r_to)
return s
#--- Files related
def modified_after(first_path, second_path):
"""Returns True if first_path's mtime is higher than second_path's mtime."""
try:
first_mtime = io.stat(first_path).st_mtime
except EnvironmentError:
return False
try:
second_mtime = io.stat(second_path).st_mtime
except EnvironmentError:
return True
return first_mtime > second_mtime
def find_in_path(name, paths=None):
"""Search for `name` in all directories of `paths` and return the absolute path of the first
occurrence. If `paths` is None, $PATH is used.
"""
if paths is None:
paths = os.environ['PATH']
if isinstance(paths, str): # if it's not a string, it's already a list
paths = paths.split(os.pathsep)
for path in paths:
if op.exists(op.join(path, name)):
return op.join(path, name)
return None
@io.log_io_error
def delete_if_empty(path, files_to_delete=[]):
''' Deletes the directory at 'path' if it is empty or if it only contains files_to_delete.
'''
if not io.exists(path) or not io.isdir(path):
return
contents = io.listdir(path)
if any(name for name in contents if (name not in files_to_delete) or io.isdir(path + name)):
return False
for name in contents:
io.remove(path + name)
io.rmdir(path)
return True
def open_if_filename(infile, mode='rb'):
"""
infile can be either a string or a file-like object.
if it is a string, a file will be opened with mode.
Returns a tuple (shouldbeclosed,infile) infile is a file object
"""
if isinstance(infile, Path):
return (io.open(infile, mode), True)
if isinstance(infile, str):
return (open(infile, mode), True)
else:
return (infile, False)
def ensure_folder(path):
"Create `path` as a folder if it doesn't exist."
if not op.exists(path):
os.makedirs(path)
def ensure_file(path):
"Create `path` as an empty file if it doesn't exist."
if not op.exists(path):
open(path, 'w').close()
def delete_files_with_pattern(folder_path, pattern, recursive=True):
"""Delete all files (or folders) in `folder_path` that match the glob `pattern`.
"""
to_delete = glob.glob(op.join(folder_path, pattern))
for fn in to_delete:
if op.isdir(fn):
shutil.rmtree(fn)
else:
os.remove(fn)
if recursive:
subpaths = [op.join(folder_path, fn) for fn in os.listdir(folder_path)]
subfolders = [p for p in subpaths if op.isdir(p)]
for p in subfolders:
delete_files_with_pattern(p, pattern, True)
class FileOrPath:
def __init__(self, file_or_path, mode='rb'):
self.file_or_path = file_or_path
self.mode = mode
self.mustclose = False
self.fp = None
def __enter__(self):
self.fp, self.mustclose = open_if_filename(self.file_or_path, self.mode)
return self.fp
def __exit__(self, exc_type, exc_value, traceback):
if self.fp and self.mustclose:
self.fp.close()