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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 Lesson 25
Step1:  However, it cannot match multiple repititions
Step2:  We can use this to find strings that may or may not include elements, like phone numbers with and without area codes.
Step3:  The '*' Regex Operater
The * character can be used to match many (0 or n)  times.
Step4:  The '+' Regex Operater
The + character can match one or more (1 or n) times.
Step5:  All of these characters can be escaped for literal matches
Step6:  The '{}' Regex Operater
The {x} character can match x times.
Step7:  This operator can also take the {x,y} argument to create a minimum or maximum number of repititions.
Step8:  RegEx does greedy matches, which means it will try to find the longest string that matches, not the shortest.
Step9:  You can do a non-greedy match by using a '}?' operator.
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Python Code:
import re
batRegex = re.compile(r'Bat(wo)?man') # The ()? says this group can appear 0 or 1 times to match; it is optional
mo = batRegex.search('The Adventures of Batman')
print(mo.group())
mo = batRegex.search('The Adventures of Batwoman')
print(mo.group())
Explanation: Lesson 25:
RegEx groups and the Pipe Character
The | pipe character can match one of many groups, but you may want a certain number of repitions of a group.
The '?' Regex Operater
The ? RegEx operater allows for optional (0 or 1) matches:
End of explanation
mo = batRegex.search('The Adventures of Batwowowowoman')
print(mo.group())
Explanation: However, it cannot match multiple repititions:
End of explanation
phoneNumRegex = re.compile(r'\d\d\d\-\d\d\d-\d\d\d\d') # this requires an area code.
mo = phoneNumRegex.search('My number is 415-555-4242') # matches
print(mo.group())
mo2 = phoneNumRegex.search('My number is 555-4242') # will not match
print(mo2)
phoneNumRegex = re.compile(r'(\d\d\d\-)?\d\d\d-\d\d\d\d') # Make first three digits and dash optional
mo = phoneNumRegex.search('My number is 415-555-4242') # matches
print(mo.group())
mo2 = phoneNumRegex.search('My number is 555-4242') # matches
print(mo2.group())
Explanation: We can use this to find strings that may or may not include elements, like phone numbers with and without area codes.
End of explanation
import re
batRegex = re.compile(r'Bat(wo)*man') # The ()* says this group can appear 0 or n times to match
print(batRegex.search('The Adventures of Batwoman').group())
print(batRegex.search('The Adventures of Batwowowowoman').group())
Explanation: The '*' Regex Operater
The * character can be used to match many (0 or n)  times.
End of explanation
import re
batRegex = re.compile(r'Bat(wo)+man') # The ()+ says this group can appear 1 or n times; it is NOT optional
print(batRegex.search('The Adventures of Batwoman').group())
print(batRegex.search('The Adventures of Batwowowowoman').group())
print(batRegex.search('The Adventures of Batman').group())
Explanation: The '+' Regex Operater
The + character can match one or more (1 or n) times.
End of explanation
import re
batRegex = re.compile(r'\+\*\?') # The +,*, and ? are escaped. 
print(batRegex.search('I learned about +*? RegEx syntax').group())
Explanation: All of these characters can be escaped for literal matches:
End of explanation
haRegex = re.compile(r'(Ha){3}')
print(haRegex.search('HaHaHa').group())
print(haRegex.search('HaHaHaHa').group())  # Matches only three times, so returns only 3
#print(haRegex.search('HaHa').group()) # No Match
phoneRegex = re.compile(r'((\d)?\d\d\d(\d)?){3}') # Useful to avoid repitition
phoneNumRegex.search('My number is 415-555-4242').group()
Explanation: The '{}' Regex Operater
The {x} character can match x times.
End of explanation
haRegex = re.compile(r'(Ha){3,5}')
print(haRegex.search('HaHaHa').group())
print(haRegex.search('HaHaHaHa').group())
print(haRegex.search('HaHaHaHaHa').group())  
print(haRegex.search('HaHaHaHaHaHaHaHa').group()) # Matches max of 5
haRegex = re.compile(r'(Ha){,5}') # Can drop one or the other for unbounded matches
print(haRegex.search('Ha').group())
print(haRegex.search('HaHa').group())
print(haRegex.search('HaHaHa').group())
print(haRegex.search('HaHaHaHa').group())
print(haRegex.search('HaHaHaHaHa').group())  
print(haRegex.search('HaHaHaHaHaHaHaHa').group()) # Matches max of 5
Explanation: This operator can also take the {x,y} argument to create a minimum or maximum number of repititions.
End of explanation
haRegex = re.compile(r'(Ha){1,6}') # at least 1, or 6
print(haRegex.search('HaHaHaHaHaHaHaHa').group()) # Matches longest string; 6
Explanation: RegEx does greedy matches, which means it will try to find the longest string that matches, not the shortest.
End of explanation
haRegex = re.compile(r'(Ha){1,6}?') # The }? says favor the first condition, not the second; non-greedy
print(haRegex.search('HaHaHaHaHaHaHaHa').group()) # Matches shortest string, 1
Explanation: You can do a non-greedy match by using a '}?' operator.
End of explanation
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