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Merge https://github.com/flopezluis/python_koans

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2 parents bfdebc5 + bb0cb4b commit 53d87d252ca04cc570b092b97df45501f033fd4b @gregmalcolm committed Feb 6, 2011
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  1. +238 −0 python 2/koans/about_regex.py
  2. +6 −0 python 2/koans/regex_cvs
  3. +28 −0 python 2/koans/regex_solutions.txt
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+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from runner.koan import *
+import re
+class AboutRegex(Koan):
+ """
+ This koans are based on the Ben's book: Regular Expressions in 10 minutes.
+ I found this books very useful so I decided to write a koans in order to practice everything I had learned from it.
+ http://www.forta.com/books/0672325667/
+ """
+
+ def test_matching_literal_text(self):
+ """
+ Lesson 1 Matching Literal String
+ """
+ string = "Hello, my name is Felix and this koans are based on the Ben's book: Regular Expressions in 10 minutes."
+ m = re.search(__, string)
+ self.assertTrue(m and m.group(0) and m.group(0)== 'Felix', "I want my name")
+
+ def test_matching_literal_text_how_many(self):
+ """
+ Lesson 1 How many matches?
+
+ The default behaviour of most regular extression engines is to return just the first match.
+ In python you have the next options:
+
+ match() --> Determine if the RE matches at the beginning of the string.
+ search() --> Scan through a string, looking for any location where this RE matches.
+ findall() --> Find all substrings where the RE matches, and returns them as a list.
+ finditer() --> Find all substrings where the RE matches, and returns them as an iterator.
+
+ """
+ string = "Hello, my name is Felix and this koans are based on the Ben's book: Regular Expressions in 10 minutes. Repeat My name is Felix"
+ m = re.match('Felix', string) #TIP: Maybe match it's not the best option
+ self.assertEqual(len(m),2, "I want to know how many times appears my name")
+
+ def test_matching_literal_text_not_case_sensitivity(self):
+ """
+ Lesson 1 Matching Literal String non case sensitivity.
+ Most regex implementations also support matches that are not case sensitive. In python you can use re.IGNORECASE, in
+ Javascript you can specify the optional i flag.
+ In Ben's book you can see more languages.
+
+ """
+ string = "Hello, my name is Felix or felix and this koans are based on the Ben's book: Regular Expressions in 10 minutes."
+ self.assertEqual(len(re.findall("felix", string,__)),2, "I want my name")
+
+ def test_matching_any_character(self):
+ """
+ Lesson 1 Matching any character
+
+ . matches any character, alphabetic characters, digits and .
+ """
+ string = "pecks.xlx\n" \
+ + "orders1.xls\n" \
+ + "apec1.xls\n" \
+ + "na1.xls\n" \
+ + "na2.xls\n" \
+ + "sa1.xls"
+
+ #TIP: remember the issue of this lesson
+ self.assertEquals(len(re.findall(__, string)),3, "I want to find all files for North America(na) or South America(sa)")
+
+ def test_matching_special_character(self):
+ """
+ Lesson 1 Matching special character
+
+ Uses \ if you want to match special character
+ """
+ string = "sales.xlx\n" \
+ + "sales1.xls\n" \
+ + "orders1.xls\n" \
+ + "apac1.xls\n" \
+ + "sales2.xls\n" \
+ + "na1.xls\n" \
+ + "na2.xls\n" \
+ + "sa1.xls"
+ #TIP you can use the pattern .a. which matches in above test but in this case matches more than you want
+ self.assertEquals(len(re.findall(__, string)),3, "I want to find all files for North America(na) or South America(sa)")
+
+ def test_matching_set_character(self):
+ """
+ Lesson 2 Matching sets of characters
+
+ A set of characters is defined using the metacharacters [ and ]. Everything between them is part of the set and
+ any one of the set members must match (but not all).
+ """
+ string = "sales.xlx\n" \
+ + "sales1.xls\n" \
+ + "orders3.xls\n" \
+ + "apac1.xls\n" \
+ + "sales2.xls\n" \
+ + "na1.xls\n" \
+ + "na2.xls\n" \
+ + "sa1.xls\n" \
+ + "ca1.xls"
+ #TIP you can use the pattern .a. which matches in above test but in this case matches more than you want
+ self.assertEquals(len(re.findall(__, string)),3, "I want to find all files for North America(na) or South America(sa), but not (ca)")
+
+ def test_using_character_set_ranges(self):
+ """
+ Lesson 2 Using character set ranges
+
+ The previous pattern could be [ns]a.\.xls and if a in the list had a file name sam.xls would be matched because the . matches all
+ characters, not just digits. This can be solved with Character sets.
+ You can use this pattern [ns]a[0123456789]\.xls but to simplify you can use a special metacharacter: - (hyphen). i.e [0-9]
+
+ - is only a metacharacter when used between [].
+
+ """
+ string = "sales.xlx\n" \
+ + "sales1.xls\n" \
+ + "orders3.xls\n" \
+ + "apac1.xls\n" \
+ + "sales2.xls\n" \
+ + "na1.xls\n" \
+ + "na2.xls\n" \
+ + "sa1.xls\n" \
+ + "sam.xls\n" \
+ + "ca1.xls"
+ self.assertEquals(len(re.findall(__, string)),3, "I want to find all files for North America(na) or South America(sa), but not (ca)")
+
+ def test_using_multiple_ranges(self):
+ """
+ Lesson 2 Using character set ranges
+
+ The following are valid ranges:
+ A-Z matches all uppercase characters from A to Z
+ a-z matches all uppercase characters from a to z
+ A-F matches all uppercase characters from A to F
+ A-z matches all uppercase characters from A to z. This pattern also includes characters such as [ and ^
+ Any two ASCII characters may be specified as the range start and end.
+
+ """
+ string = '<BODY BGCOLOR="#336633" TEXT="#FFFFFF" MARGINWIDTH="0" MARGINHEIGHT="0" TOPMARGIN="0" LEFTMARGIN="0">'
+ self.assertEquals(len(re.findall(__, string)),2, "I want to find all the colors in RGB")
+
+
+ def test_anything_but_matching(self):
+ """
+ Lesson 2 Using character set ranges
+ Occsionally, you'll want a list of characters that you don't want to match.
+ Character sets can be negated using the ^ metacharacter.
+
+ """
+ string = "sales.xlx\n" \
+ + "sales1.xls\n" \
+ + "orders3.xls\n" \
+ + "apac1.xls\n" \
+ + "sales2.xls\n" \
+ + "sales3.xls\n" \
+ + "europe2.xls\n" \
+ + "sam.xls\n" \
+ + "na1.xls\n" \
+ + "na2.xls\n" \
+ + "sa1.xls\n" \
+ + "ca1.xls"
+ m = re.search(__, string)
+ self.assertTrue(m and m.group(0) and m.group(0)== 'sam.xls', "I want to find the name sam")
+
+ def using_metacharacters_escaping(self):
+ """
+ Lesson 3 Using metacharacters
+
+ Metacharacters are characters that have special meaning within regular expressions.
+
+ Metacharacters can be escaped by preceding them with a backslash, therefore \. matches .
+ """
+ string = "var myArray = new Array();\n" \
+ + "if (myArray[0]) { \n" \
+ + "}"
+ m = re.search("myArray[0]", string) #TIP: This pattern matches "myArray0" because [ and ] are metacharacters
+ self.assertTrue(m and m.group(0) and m.group(0)== 'myArray[0]', "I want to find myArray[0]")
+
+ def using_metacharacters_matching_white_spaces(self):
+ """
+ Lesson 3 Matching whitespace character
+
+ Sometimes you'll have to match nonprinting whitespace characters embedded in your text. For example tab characters
+ or line breaks .
+ In this cases you can use these special metacharacters:
+ [\b] Backspace
+ \f Form feed
+ \n Line feed
+ \r Carriage return
+ \t Tab
+ \v Vertical tab
+
+ """
+ f = open('koans/regex_cvs', 'r')
+ string = f.read()
+ #This text contains a series of records in comma-delimited format (cvs). Before processing the records, you need
+ # to remove any blank lines in the data.
+ m = re.search("", string)
+ self.assertTrue(m and m.group(0) and m.group(0)== '\n\n', "I want to find the blank lines")
+
+ def using_metacharacters_matching_digits(self):
+ """
+ Lesson 3 Using metacharacters
+
+ As you have seen in Lesson 2, [0-9] is a shorcut for [0123456789] and is used to match any digit.
+ To match anything other than a digit, the set can be negated as [^0-9].
+ With the next metacharacters you can do the same:
+ \d match any digit (same as [0-9])
+ \D match any nondigit (same as [0-9])
+ """
+ string = "var myArray = new Array();\n" \
+ + "if (myArray[0]) { \n" \
+ + " alert('Learning regex'); \n" \
+ + "} \n" \
+ + "if (myArray[1]) { \n" \
+ + " alert('With this great book');\n" \
+ + "} \n"
+
+ self.assertEquals( len(re.findall(__, string)), 2, "I want to find all uses of myArray")
+
+
+ def using_metacharacters_matching_alphanumeric_characters(self):
+ """
+ Lesson 3 Using metacharacters
+
+ Like with the digits you have special characters for alphanumeric characters:
+ \w Any alphanumeric character in uppercase or lowercase and underscore: [a-zA-Z0-9_]
+ \W Any nonalphanumeric or underscore character: [^a-zA-Z0-9_]
+
+ Here you have a list of IDs made of 3 characters/digits/underscores, 1 hyphen and 3 characters/digits/underscores:
+ A1A-B_A or BA_-2e3 or 1_2-34R
+ """
+ string = "A_1-DRA\n" \
+ +"A01-2ER\n" \
+ +"A01-(4d\n" \
+ +"B11=223\n" \
+ +"A1A-B_A\n" \
+ +"1_2-34R\n" \
+ +"BA_-2e3"
+
+ self.assertEquals( len(re.findall(__, string)), 5, "I want to find the ids")
View
@@ -0,0 +1,6 @@
+"101", "Ben", "Forta
+"102", "Felix", "Lopez"
+
+"103", "Roberta", "Robertson"
+"104", "Bob", "Bobson"
+
@@ -0,0 +1,28 @@
+test_matching_literal_text:
+ Felix
+test_matching_literal_text_how_many:
+ findall
+test_matching_literal_text_not_case_sensitivity:
+ re.findall("felix", string, re.IGNORECASE)
+test_matching_any_character:
+ .a OR .a.
+test_matching_special_character:
+ .a.\.
+test_matching_set_character:
+ [ns]a.\. Actually this pattern is not quite right either. If a file named usa1.xls existed, it would match.
+ The solution to this problem involves matching, which will be covered later, in "Position Matching.
+test_using_character_set_ranges:
+ [ns]a[0-9]\.xls
+test_using_multiple_ranges:
+ #[0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f] OR #[0-9A-Fa-f]{6} but the latter will be seen later
+test_anything_but_matching:
+ [ns]a[^0-9]\.xls
+using_metacharacters_escaping:
+ myArray\[0\]
+using_metacharacters_macthing_white_spaces:
+ \n\n
+ IMPORTANT: Windows uses a carriage return line fedd combination used as an end-of-line marker, so you need to use \r\n.
+using_metacharacters_matching_digits:
+ myArray\[\d\]
+using_metacharacters_matching_alphanumeric_characters:
+ \w\w\w-\w\w\w

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