Python/Re - Revision history

Admin at 00:52, 13 April 2017

2017-04-13T00:52:48Z

← Older revision		Revision as of 00:52, 13 April 2017
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	['thing2', '2017', '04', '09', '05', '04', '67', 'csv']		['thing2', '2017', '04', '09', '05', '04', '67', 'csv']
	</pre>		</pre>





			[[Category:Regular Expressions]]
			[[Category:Python]]

2017-04-13T00:47:07Z

Splitting string at occurrences of regular expression

2017-04-12T18:33:04Z

Splitting string at occurrences of regular expression

2017-04-12T18:27:17Z

Splitting string at occurrences of regular expression

← Older revision		Revision as of 18:27, 12 April 2017
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	==Splitting string at occurrences of regular expression==		==Splitting string at occurrences of regular expression==

	To split a string at occurrences of regular expressions, use ,code>re.split(regular_expression, string)</code>. This will apply the regular expression to the string, and split the string at all occurrences of the given pattern. The pattern will be thrown away unless it is surrounded by ()s.		To split a string at occurrences of regular expressions, use <code>re.split(regular_expression, string)</code>. This will apply the regular expression to the string, and split the string at all occurrences of the given pattern. The pattern will be thrown away unless it is surrounded by ()s.

	The regular expression <code>[^a-zA-Z0-9]{1,}</code> will match non-alphanumeric characters occurring one or more times in the string, and will split the string at the locations where this pattern occurs. For example:		The regular expression <code>[^a-zA-Z0-9]{1,}</code> will match non-alphanumeric characters occurring one or more times in the string, and will split the string at the locations where this pattern occurs. For example:

2017-04-12T18:26:55Z

Extracting substring from strings using re

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 >> re.findall(r'[0-9]{4}', z)
 ['2017']
 </pre>

2017-04-12T18:16:28Z

← Older revision		Revision as of 18:16, 12 April 2017
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	[[Regular expressions]] in Python.		[[Regular expressions]] in Python.

			==Extracting substring from strings using re==

			Suppose we have a string like "thing2_2017-04-09_05-04-67.csv" and we want to extract tokens from the filename (thing2, 2017, 04, 09, etc).

			To extract particular tokens using a regular expression, we can use <code>re.findall(regular_expression,string)</code>. For example, the regular expression <code>[0-9]{4}</code> looks for the digits 0-9 occurring exactly 4 times.

			<pre>
			>>> z = "thing2_2017-04-09_05-04-67.csv"
			>> re.findall(r'[0-9]{4}', z)
			['2017']
			</pre>

2017-04-12T18:08:03Z

Created page with "Regular expressions in Python."

New page

[[Regular expressions]] in Python.