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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> | |||
Revision as of 18:16, 12 April 2017
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 re.findall(regular_expression,string). For example, the regular expression [0-9]{4} looks for the digits 0-9 occurring exactly 4 times.
>>> z = "thing2_2017-04-09_05-04-67.csv"
>> re.findall(r'[0-9]{4}', z)
['2017']