This is a collection of small pieces of Python code which are useful in other projects. While you could technically import this package and use it directly, it's mostly encouraged to take the needed functionality and embed them directly in the needed project
Automatically send output to a pager if being run through a TTY and the output is long enough, similar to git log, recent dpkg -l, etc.
with AutoPager() as pager:
for i in range(1000):
print(i, file=pager)Note that if the text sent to AutoPager is less than a screen length, it is still technically sent to a pager (pager by default, which itself is usually less), but since --quit-if-one-screen is passed to less, it will just output the text.
If STDOUT is not a TTY, no pager will be invoked, and AutoPager will function like normal print().
An extension to the croniter module, primarily adding support for Jenkins-style "H" hashing definitions, as well as "R" random definitions.
epoch = datetime(2020, 1, 1, 0, 0)
hash_id = "hello"
# Hashed daily
croniter_hash("H H * * *", epoch, hash_id=hash_id).get_next(datetime)
"""datetime.datetime(2020, 1, 1, 11, 10)"""
# Each hashed definition is consistent to its specified hash_id
croniter_hash("H H * * *", epoch, hash_id="hello").get_next(datetime)
"""datetime.datetime(2020, 1, 1, 11, 10)"""
croniter_hash("H H * * *", epoch, hash_id="hello").get_next(datetime)
"""datetime.datetime(2020, 1, 1, 11, 10)"""
croniter_hash("H H * * *", epoch, hash_id="bonjour").get_next(datetime)
"""datetime.datetime(2020, 1, 1, 20, 52)"""
# The hash_id can be binary
croniter_hash("H H * * *", epoch, hash_id=b"\x01\x02\x03\x04").get_next(datetime)
"""datetime.datetime(2020, 1, 1, 14, 53)"""
# Epoch output
croniter_hash("H H * * *", epoch, hash_id=hash_id).get_next(float)
"""1577877000.0"""
# 6th-position second formation is supported
croniter_hash("H H * * * H", epoch, hash_id=hash_id).get_next(datetime)
"""datetime.datetime(2020, 1, 1, 11, 10, 32)"""
# Named "@" definitions work too, and assume hashing to the second
croniter_hash("@daily", epoch, hash_id=hash_id).get_next(datetime)
"""datetime.datetime(2020, 1, 1, 11, 10, 32)"""An exponentially-weighted moving average, with a default weight of 8.0.
a = EWMA([1, 2])
a.average
"""1.125"""
a.items
"""2"""
a.append(3)
float(a)
"""1.359375"""
len(a)
"""3"""
a = EWMA((random() for _ in range(1000000)))
a.average
"""0.5001567190631783"""
a.items
"""1000000"""
a.sum
"""499919.5894089916"""Formats numbers into human-pleasing representation. Supports string and F-string formatting, binary SI prefixes, and customizable rollover points.
# Basic repr formatting
numfmt(12345)
"""12.35 k"""
numfmt(12345, fmt="{num.real:0.09f} {num.prefix}")
"""12.345000000 k"""
# Positional or named attributes
"{0.real:0.03f} {0.prefix}B".format(numfmt(12345))
"""12.345 kB"""
"{num.real:0.01f} {num.prefix}B/s".format(num=numfmt(12345))
"""12.3 kB/s"""
# F-strings
num = numfmt(12345); f"{num.real:0.04f} {num.prefix}B"
"""12.3450 kB"""
# Named attributes, binary SI prefixes
"{num.real:0.02f} {num.prefix}B".format(num=numfmt(12345, binary=True))
"""12.06 KiB"""
# Rollover before 100% of a normal prefix change
"{num.real:0.02f} {num.prefix}B".format(num=numfmt(897306, rollover=0.9))
"""897.31 kB"""
"{num.real:0.02f} {num.prefix}B".format(num=numfmt(973829, rollover=0.9))
"""0.97 MB"""
# Rollover after 100% of a normal prefix change
"{num.real:0.02f} {num.prefix}B".format(num=numfmt(1032456, rollover=1.1))
"""1032.46 kB"""
"{num.real:0.02f} {num.prefix}B".format(num=numfmt(1122334, rollover=1.1))
"""1.12 MB"""
# Limit number of prefix changes
"{num.real:0.02f} {num.prefix}B".format(num=numfmt(123000000000, limit=2))
"""123000.00 MB"""A block-based iterable wrapper around filehandle read(), allowing for an iterating loop without needing to check for the filehandle end sentinel.
import hashlib
sha = hashlib.sha256()
with open("/bin/ls", "rb") as fh:
for block in readiter(fh):
sha.update(block)
sha.hexdigest()
"""1e39354a6e481dac48375bfebb126fd96aed4e23bab3c53ed6ecf1c5e4d5736d"""
with open("/etc/shells", "r") as fh:
for count, block in enumerate(readiter(fh, size=10)):
pass
count
"""22"""(Try to) safely write files with minimum collision possibility, by writing to a temporary file and then moving into final place upon filehandle close.
The filehandle object otherwise performs identically to a real open() filehandle.
with safe_write("foo") as f:
print("Current filename open is: {}".format(f.name))
print("Upon close, {} will be moved to {}".format(f.name, f.dest_name))
f.write("bar")
"""Current filename open is: foo.tmp726c0df7-276e-4d51-b99b-2632855d7bef~"""
"""Upon close, foo.tmp726c0df7-276e-4d51-b99b-2632855d7bef~ will be moved to foo"""
"""3"""
os.stat("foo")
"""os.stat_result(st_mode=33204, st_ino=48500857, st_dev=64768, st_nlink=1,
st_uid=1000, st_gid=1000, st_size=3, st_atime=1617931328,
st_mtime=1617931328, st_ctime=1617931328)"""An implementation of the Super Mario World random number generator, based on deconstruction by Retro Game Mechanics Explained. This is obviously not a cryptographically secure random number generator, as it has a fixed initial seed and only has a unique cycle of 27776 runs.
smwrand = SMWRand()
for i in range(5):
r = smwrand.rand()
print("Seed (post-output): 0x{:02x} 0x{:02x}, output: 0x{:02x} 0x{:02x}".format(
smwrand.seed_1, smwrand.seed_2, r[0], r[1],
))
"""
Seed (post-output): 0x06 0x03, output: 0x05 0x00
Seed (post-output): 0x9c 0x0f, output: 0x93 0x18
Seed (post-output): 0x42 0x3e, output: 0x7c 0x12
Seed (post-output): 0x78 0xf8, output: 0x80 0x37
Seed (post-output): 0xbe 0xe3, output: 0x5d 0xa8
"""Werder creates word-like werds; words which are (usually) pronounceable but are otherwise randomly assembled. Useful as a replacement for places where a word list is used in human-readable identifiers (though werder is certainly capable of generating offensive words).
werder = Werder()
werder.werd()
"""koowio"""
werder.sentence()
"""Lols blusifuly plart obud quustest oathakoord?"""Copyright (c) 2020-2021 Ryan Finnie
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.