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Split - regular expression v literal string
String Handling example from a Well House Consultants training course
More on String Handling [link]
Source code: qre Module: Y108
""" If you want to divide a line into a number of fields
with a particular character as the delimiter, there's a split method that works on strings, and you pass it the separator character as a parameter. There's a second split method - in the re (regular expression) class which lets you define a pattern on which to split - on (for example) a whole series of white spaces. But be careful - if you want to use the second form of split, you need to run the method on the regular expression object, and pass in the string that you're splitting. They are the opposite way round! Why - when Python usually prides itself on its OO credientials and polymorphism - are the two calling sequences inverted? Split on a string - like the rest of the string methods - takes the source string it's to work on as its input object. So it follows a pattern. Split on a regular expression must operate on a regular expression object to ensure that the correct method is called, and when you're splitting, the only regular expression you're using is the split pattern. So in this case, the object it runs on has to be the pattern - i.e. the other way around! """ import re space = re.compile(r'\s+') summat = "Andrew Fishing Punting Whinging" # String split a1 = summat.split(" ") # Regular Expression split a2 = space.split(summat) print(a1) print(a2) """ Result of running WomanWithCat:y108 grahamellis$ python2 qre ['Andrew', '', 'Fishing', 'Punting', 'Whinging'] ['Andrew', 'Fishing', 'Punting', 'Whinging'] WomanWithCat:y108 grahamellis$ python3 qre ['Andrew', '', 'Fishing', 'Punting', 'Whinging'] ['Andrew', 'Fishing', 'Punting', 'Whinging'] WomanWithCat:y108 grahamellis$ """ Learn about this subject
This module and example are covered on the following public courses:
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