Python programming - Revision history

Paul: /* split function */

2025-01-19T00:13:01Z

split function

← Older revision		Revision as of 19:13, 18 January 2025
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	=== split function ===		=== split function ===

	HOWTO use [https://docs.python.org/3/library/stdtypes.html#string-methods Python's split()] on a text using ASCII decimal 29 [https://en.wikipedia.org/wiki/C0_and_C1_control_codes#Field_separators Group Separator] for separator.		HOWTO use [https://docs.python.org/3/library/stdtypes.html#string-methods Python's split()] on text using ASCII decimal 29 [https://en.wikipedia.org/wiki/C0_and_C1_control_codes#Field_separators Group Separator] for separator.

	Define your ASCII char <code>.split(chr(29))</code>		Define your ASCII char <code>.split(chr(29))</code>

Paul: /* Conditionals */

2025-01-19T00:02:22Z

Conditionals

← Older revision		Revision as of 19:02, 18 January 2025
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	'73dcd936' < -- IPv4 representation in compact hexadecimal format</pre>		'73dcd936' < -- IPv4 representation in compact hexadecimal format</pre>

			=== split function ===

			HOWTO use [https://docs.python.org/3/library/stdtypes.html#string-methods Python's split()] on a text using ASCII decimal 29 [https://en.wikipedia.org/wiki/C0_and_C1_control_codes#Field_separators Group Separator] for separator.

			Define your ASCII char <code>.split(chr(29))</code>

			Example:
			<pre>text_to_split.split(chr(29))</pre>

	=== Conditionals ===		=== Conditionals ===

Paul: /* Python string formatting */

2023-02-14T03:42:33Z

Python string formatting

← Older revision		Revision as of 22:42, 13 February 2023
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	[https://saralgyaan.com/posts/f-string-in-python-usage-guide/ f string Python usage guide]		[https://saralgyaan.com/posts/f-string-in-python-usage-guide/ f string Python usage guide]

			[https://zetcode.com/python/fstring/ Python f-string tutorial]

	==== comma and [https://docs.python.org/3.7/library/string.html#format-specification-mini-language fixed-point notation] examples ====		==== comma and [https://docs.python.org/3.7/library/string.html#format-specification-mini-language fixed-point notation] examples ====

Paul: /* Python datetime module */

2023-02-14T03:41:06Z

Python datetime module

← Older revision		Revision as of 22:41, 13 February 2023
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	'20190401034018.177Z'</pre>		'20190401034018.177Z'</pre>

			Same example with f-string

			<pre>f'{datetime.utcnow():%Y%m%d%H%M%S.%f}'[:-3]+'Z'</pre>

	== Working with [http://json.org JSON] in Python ==		== Working with [http://json.org JSON] in Python ==

Paul: /* HOWTO get an ISO 8601 or ASN.1 GeneralizedTime time format with Python datetime object */

2023-02-14T03:06:31Z

HOWTO get an ISO 8601 or ASN.1 GeneralizedTime time format with Python datetime object

Paul: /* HOWTO get an ISO 8601 or ASN.1 GeneralizedTime time format out of Python datetime object */

2023-02-14T03:04:02Z

HOWTO get an ISO 8601 or ASN.1 GeneralizedTime time format out of Python datetime object

← Older revision		Revision as of 22:04, 13 February 2023
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	[https://blog.ganssle.io/articles/2019/11/utcnow.html Stop using utcnow and utcfromtimestamp]		[https://blog.ganssle.io/articles/2019/11/utcnow.html Stop using utcnow and utcfromtimestamp]

	=== HOWTO get an [https://en.wikipedia.org/wiki/ISO_8601 ISO 8601] or [https://www.obj-sys.com/asn1tutorial/node14.html ASN.1 GeneralizedTime] time format ~~out of~~ Python datetime object ===		=== HOWTO get an [https://en.wikipedia.org/wiki/ISO_8601 ISO 8601] or [https://www.obj-sys.com/asn1tutorial/node14.html ASN.1 GeneralizedTime] time format with Python datetime object ===

	<pre>>>> import datetime		<pre>>>> import datetime

Paul: /* Python string formatting */

2023-01-15T03:00:06Z

Python string formatting

← Older revision		Revision as of 22:00, 14 January 2023
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	[https://docs.python.org/3/library/time.html#time.strftime time.strftime] and use %f to get microseconds		[https://docs.python.org/3/library/time.html#time.strftime time.strftime] and use %f to get microseconds

			[https://saralgyaan.com/posts/f-string-in-python-usage-guide/ f string Python usage guide]

	==== comma and [https://docs.python.org/3.7/library/string.html#format-specification-mini-language fixed-point notation] examples ====		==== comma and [https://docs.python.org/3.7/library/string.html#format-specification-mini-language fixed-point notation] examples ====

Paul: added datetime usage example

2022-04-24T02:13:51Z

added datetime usage example

← Older revision		Revision as of 21:13, 23 April 2022
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	[https://docs.python.org/3/library/datetime.html datetime] module supplies classes for manipulating dates and times in both simple and complex ways.		[https://docs.python.org/3/library/datetime.html datetime] module supplies classes for manipulating dates and times in both simple and complex ways.

			[https://docs.python.org/3/library/datetime.html#examples-of-usage-datetime Examples of datetime usage]

	[https://docs.python.org/3/library/datetime.html#strftime-and-strptime-behavior strftime and strptime behavior]		[https://docs.python.org/3/library/datetime.html#strftime-and-strptime-behavior strftime and strptime behavior]

Paul: added section for writing to CSV

2022-04-22T22:54:36Z

added section for writing to CSV

← Older revision		Revision as of 17:54, 22 April 2022
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	[https://docs.python.org/3/library/json.html JSON encoder and decoder] including making JSON beautiful.		[https://docs.python.org/3/library/json.html JSON encoder and decoder] including making JSON beautiful.

			== Writing data to CSV ==

			[https://www.pythontutorial.net/python-basics/python-write-csv-file/ Python write CSV file tutorial]

	== Python Network Programming ==		== Python Network Programming ==

Paul: added link to My Python list notes

2022-02-07T17:14:04Z

added link to My Python list notes

← Older revision		Revision as of 12:14, 7 February 2022
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	[[My Python dictionary notes]]		[[My Python dictionary notes]]

			[[My Python list notes]]

	<big>Create empty lists, dictionaries, sets</big>		<big>Create empty lists, dictionaries, sets</big>

← Older revision		Revision as of 22:06, 13 February 2023
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	datetime.datetime(2019, 3, 31, 21, 30, 4, 999219)		datetime.datetime(2019, 3, 31, 21, 30, 4, 999219)

	>>> d = datetime.now()		>>> d = datetime.now()

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	datetime.datetime(2019, 3, 31, 21, 30, 51, 362520)		datetime.datetime(2019, 3, 31, 21, 30, 51, 362520)

	>>> f = '{:%Y%m%d%H%M%S.%f}' < -- Setup a string format to control the datetime format.		>>> f = '{:%Y%m%d%H%M%S.%f}' < -- Setup a string format to control the datetime format.

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	'20190331213051.362520' < -- microsecond accuracy		'20190331213051.362520' < -- microsecond accuracy

	>>> d2 = datetime(2019, 3, 31, 21, 30, 51, 000000) < -- Create datetime object with exactly zero microseconds to verify string format.		>>> d2 = datetime(2019, 3, 31, 21, 30, 51, 000000) < -- Create datetime object with exactly zero microseconds to verify string format.

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	'20190331213051.000000' < -- verified that datetime displays six zeros		'20190331213051.000000' < -- verified that datetime displays six zeros

	>>> '20190331213051.000000'[:-3] < -- truncate last three digits		>>> '20190331213051.000000'[:-3] < -- truncate last three digits

	'20190331213051.000' < -- Now we need timezone offset		'20190331213051.000' < -- Now we need timezone offset

	>>> z = datetime.datetime.utcnow() < -- I want UTC time so I use datetime class method utcnow()		>>> z = datetime.datetime.utcnow() < -- I want UTC time so I use datetime class method utcnow()

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	datetime.datetime(2019, 4, 1, 3, 28, 53, 152240) < -- not in format I want		datetime.datetime(2019, 4, 1, 3, 28, 53, 152240) < -- not in format I want

	>>> f.format(z) < -- apply format specification used above		>>> f.format(z) < -- apply format specification used above

	'20190401032853.152240' < -- want to remove least 3 insignificant digits from microseconds		'20190401032853.152240' < -- want to remove least 3 insignificant digits from microseconds

	>>> f.format(z)[:-3]		>>> f.format(z)[:-3]

	'20190401032853.152' < -- missing offset		'20190401032853.152' < -- missing offset

	>>> f.format(z)[:-3]+'Z' < -- simple string concatenate		>>> f.format(z)[:-3]+'Z' < -- simple string concatenate