Replace KB unit with KiB #4293

vstinner · 2017-11-06T09:42:22Z

kB (kilo byte) unit means 1000 bytes, whereas KiB ("kibibyte")
means 1024 bytes. KB was misused: replace kB or KB with KiB when
appropriate.

Same change for MB and GB which become MiB and GiB.

Change the output of Tools/iobench/iobench.py.

Round also the size of the documentation from 5.5 MB to 5 MiB.

vstinner · 2017-11-06T09:42:32Z

https://en.wikipedia.org/wiki/Kibibyte

serhiy-storchaka · 2017-11-06T09:50:41Z

Lib/distutils/cygwinccompiler.py

@@ -234,8 +234,8 @@ def link(self, target_desc, objects, output_filename, output_dir=None,
        # who wants symbols and a many times larger output file
        # should explicitly switch the debug mode on
        # otherwise we let dllwrap/ld strip the output file
-        # (On my machine: 10KB < stripped_file < ??100KB
-        #   unstripped_file = stripped_file + XXX KB
+        # (On my machine: 10KiB < stripped_file < ??100KiB


I'm not sure the difference between KB and KiB is important here.

serhiy-storchaka · 2017-11-06T09:53:01Z

Tools/iobench/iobench.py

@@ -29,9 +29,9 @@ def text_open(fn, mode, encoding=None):
        return open(fn, mode)

 def get_file_sizes():
-    for s in ['20 KB', '400 KB', '10 MB']:
+    for s in ['20 KiB', '400 KiB', '10 MiB']:


This file should be kept compatible with both Python 2.6 and Python >= 3.0.

Changing the output format will make harder comparing results between versions.

This script is compatible with Python 2.7 (I didn't test Python 2.6).

If the output must be the same with the script in Python 2.7, I can update Python 2.7 as well.

@pitrou: Since you wrote the script, what do you think?

No problem from me.

serhiy-storchaka · 2017-11-06T09:53:29Z

setup.py

@@ -907,7 +907,7 @@ def detect_modules(self):
                missing.append('_hashlib')

        # We always compile these even when OpenSSL is available (issue #14693).
-        # It's harmless and the object code is tiny (40-50 KB per module,
+        # It's harmless and the object code is tiny (40-50 KiB per module,


This is approximate value.

serhiy-storchaka · 2017-11-06T10:00:45Z

It may be worth to correct also MB and GB (as in f8def28). But not all decimal prefixes can be changed.

vstinner · 2017-11-06T10:12:35Z

It may be worth to correct also MB and GB (as in f8def28).

Done.

serhiy-storchaka

There are cases where a space between digits and unit is missed, like 256KB.

serhiy-storchaka · 2017-11-06T10:17:24Z

Doc/tools/templates/download.html

  </tr>
 <tr><td>EPUB</td>
-    <td><a href="{{ dlbase }}/python-{{ release }}-docs.epub">Download</a> (ca. 5.5 MB)</td>
+    <td><a href="{{ dlbase }}/python-{{ release }}-docs.epub">Download</a> (ca. 5.5 MiB)</td>


Are you sure the size in MB and MiB is the same? Are binary prefixes preferenced here?

I'm quite sure that the file size were compute with an unit of 1024 * 1024 bytes, MiB.

The size of epub-file in 3.7 is 5.426 MB or 5.175 MiB. 5.5 is closer to 5.426, but in any case this is an approximate estimation. The question is what unit is more human-readable. What units are used by a file manager in Windows and OS X?

What units are used by a file manager in Windows and OS X?

https://blogs.msdn.microsoft.com/oldnewthing/20090611-00/?p=17933

"Explorer is just following existing practice. Everybody (to within experimental error) refers to 1024 bytes as a kilobyte, not a kibibyte."

I prefer KiB rather than KB since KiB is defined as 1024 bytes, whereas KB (or kB) may be 1000 or 1024 bytes.

The size of epub-file in 3.7 is 5.426 MB or 5.175 MiB. 5.5 is closer to 5.426, but in any case this is an approximate estimation.

I don't think that it's interesting to give the file size. If we want to keep it, maybe we should drop digits after the dot.

These numbers are likely outdated, it's very hard to keep them up to date.

If Windows Explorer uses the multiplier 1024 but call it KB, it is good to use binary prefixes here. If it uses the multiplier 1000, perhaps it is better to use decimal prefixes.

If it uses the multiplier 1000, perhaps it is better to use decimal prefixes.

I'm not aware of any application using decimal prefixes...

The volume of hard disks usually is specified with decimal prefixes.

I just have tested, Windows uses binary multipliers (but decimal prefixes), thus it is better to use binary multipliers for getting the same numbers, but with correct binary prefixes.

Hard drive manufacturers use decimal prefixes, all software I know of uses binary. That's most of the cause behind a 3 TB drive appearing as 2.7 GB to Windows/Linux.

That said, unless you actually care about byte-precision, 5.5 MB is mentally equivalent to 5.5 MiB, or 6 MB, or 5 MB.

serhiy-storchaka · 2017-11-06T16:33:09Z

Please look also on cases where unit is not separated by a space from a number.

vstinner · 2017-11-08T17:39:55Z

@serhiy-storchaka: "Please look also on cases where unit is not separated by a space from a number."

Oh, I missed them. Right, there were many of them :-)

I rebased and completed my PR.

vstinner · 2017-11-08T17:41:08Z

I found one place in Python where "kB" means 1000 B: the bz2 module. The compression level is the block size in number of 100,000 B. I replaced 100 kB with 100,000 B to prevent any risk of confusion.

vstinner · 2017-11-08T17:42:56Z

I chose to write "100,000 B" since it's what I found in the official bzip2 documentation:

http://www.bzip.org/1.0.5/bzip2-manual-1.0.5.html#memory-management

The flags -1 through -9 specify the block size to be 100,000 bytes through 900,000 bytes (the default) respectively.

serhiy-storchaka · 2017-11-08T18:27:02Z

But writing some numbers (like (2 << 25)) looks strange to me. I would write (1 << 26) or (64 << 20).

kB (*kilo* byte) unit means 1000 bytes, whereas KiB ("kibibyte") means 1024 bytes. KB was misused: replace kB or KB with KiB when appropriate. Same change for MB and GB which become MiB and GiB. Change the output of Tools/iobench/iobench.py. Round also the size of the documentation from 5.5 MB to 5 MiB.

vstinner · 2017-11-08T22:42:49Z

I replaced "900,000 B" with "900,000 bytes". "B" unit is rarely written like that, usually it's more "bytes".

vstinner added skip issue skip news labels Nov 6, 2017

vstinner requested a review from serhiy-storchaka November 6, 2017 09:42

the-knights-who-say-ni added the CLA signed label Nov 6, 2017

bedevere-bot added the awaiting merge label Nov 6, 2017

vstinner mentioned this pull request Nov 6, 2017

bpo-29659: Expose copyfileobj() length arg for public use #328

Closed

serhiy-storchaka reviewed Nov 6, 2017

View reviewed changes

serhiy-storchaka approved these changes Nov 8, 2017

View reviewed changes

vstinner merged commit 8c663fd into python:master Nov 8, 2017

bedevere-bot removed the awaiting merge label Nov 8, 2017

vstinner deleted the kib branch November 8, 2017 22:44

andresdelfino mentioned this pull request Oct 6, 2018

Update download.html to reflect the unit change #9639

Closed

vstinner mentioned this pull request Jul 31, 2019

bpo-18049: Sync thread stack size to main thread size on macOS #14748

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Replace KB unit with KiB #4293

Replace KB unit with KiB #4293

vstinner commented Nov 6, 2017 •

edited

Loading

vstinner commented Nov 6, 2017

serhiy-storchaka Nov 6, 2017

serhiy-storchaka Nov 6, 2017

vstinner Nov 6, 2017

pitrou Nov 6, 2017

serhiy-storchaka Nov 6, 2017

serhiy-storchaka commented Nov 6, 2017

vstinner commented Nov 6, 2017

serhiy-storchaka left a comment

serhiy-storchaka Nov 6, 2017

vstinner Nov 6, 2017

serhiy-storchaka Nov 6, 2017

vstinner Nov 6, 2017

serhiy-storchaka Nov 6, 2017

vstinner Nov 6, 2017

serhiy-storchaka Nov 6, 2017

nicktimko Nov 7, 2017

serhiy-storchaka commented Nov 6, 2017

vstinner commented Nov 8, 2017

vstinner commented Nov 8, 2017

vstinner commented Nov 8, 2017

serhiy-storchaka commented Nov 8, 2017

vstinner commented Nov 8, 2017

Replace KB unit with KiB #4293

Replace KB unit with KiB #4293

Conversation

vstinner commented Nov 6, 2017 • edited Loading

vstinner commented Nov 6, 2017

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

serhiy-storchaka commented Nov 6, 2017

vstinner commented Nov 6, 2017

serhiy-storchaka left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

serhiy-storchaka commented Nov 6, 2017

vstinner commented Nov 8, 2017

vstinner commented Nov 8, 2017

vstinner commented Nov 8, 2017

serhiy-storchaka commented Nov 8, 2017

vstinner commented Nov 8, 2017

vstinner commented Nov 6, 2017 •

edited

Loading