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Python Regular Expressions in Python Introduction to Regular Expressions Compiling and Loops

Posted by Mark Chesney
Mark Chesney
11,747 Points

regex players dictionary and class

Hi. Can someone please help? The code below only shows the first entry, not all of them. Thanks in advance!

import re

string = '''Love, Kenneth: 20
Chalkley, Andrew: 25
McFarland, Dave: 10
Kesten, Joy: 22
Stewart Pinchback, Pinckney Benton: 18'''

players = re.search(r"""
    ^(?P<last_name>[\w ]*),[\s]
    (?P<first_name>[\w ]*):[\s]
    (?P<score>[\d]{2})$
""", string, re.X | re.M)

print(players.group())
print(players.groupdict())

4 Answers

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

You are on the right track. re.search only returns the first match. Perhaps you meant to use re.findall which returns a list of matches:

import re

string = '''Love, Kenneth: 20
Chalkley, Andrew: 25
McFarland, Dave: 10
Kesten, Joy: 22
Stewart Pinchback, Pinckney Benton: 18'''

players = re.findall(r"""
    ^(?P<last_name>[\w ]*),[\s]
    (?P<first_name>[\w ]*):[\s]
    (?P<score>[\d]{2})$
""", string, re.X | re.M)

print(players)
# [(‘Love’, ‘Kenneth’, ‘20’), (‘Chalkley’, ‘Andrew’, ‘25’), (‘McFarland’, ‘Dave’, ‘10’), (‘Kesten’, ‘Joy’, ‘22’), (‘Stewart Pinchback’, ‘Pinckney Benton’, ‘18’)]

Post back if you need more help. Good luck!!!

Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

There is also re.finditer which produces an iterator:

import re

string = '''Love, Kenneth: 20
Chalkley, Andrew: 25
McFarland, Dave: 10
Kesten, Joy: 22
Stewart Pinchback, Pinckney Benton: 18'''

matches = re.finditer(r"""
    ^(?P<last_name>[\w ]*),[\s]
    (?P<first_name>[\w ]*):[\s]
    (?P<score>[\d]{2})$
""", string, re.X | re.M)

for match in matches:
    print(match.groupdict())

# {'last_name': 'Love', 'score': '20', 'first_name': 'Kenneth'}
# {'last_name': 'Chalkley', 'score': '25', 'first_name': 'Andrew'}
# {'last_name': 'McFarland', 'score': '10', 'first_name': 'Dave'}
# {'last_name': 'Kesten', 'score': '22', 'first_name': 'Joy'}
# {'last_name': 'Stewart Pinchback', 'score': '18', 'first_name': 'Pinckney Benton'}
Mark Chesney
Mark Chesney
11,747 Points
Mark Chesney
Mark Chesney
11,747 Points

Thanks Chris! Okay, what you're saying making sense. Now can we get all the players into a grouped dict-like expression? Your code returns all players but ungrouped :|

Chris Guy
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Chris Guy
Python Web Development Techdegree Graduate 14,615 Points
Chris Guy
.a{fill-rule:evenodd;}techdegree seal-36
Chris Guy
Python Web Development Techdegree Graduate 14,615 Points

Hi all,

Following on from Mark Chesney 's question above, I am stuck on how to iterate through matches to create instances of a class. Specifically I am struggling with this code challenge:

Wow! OK, now, create a class named Player that has those same three attributes, last_name, first_name, and score. I should be able to set them through init.

I have changed the regex to use re.finditer and added a class with an init function. When I run this in the console I can create an instance of the Player class which contains the player info from the final iteration of the loop.

So my questions are

  1. How would I go about creating a separate instance of the class for each of the players?
  2. How do i pass this specific challenge as the code below gives a Bummer: players doesn't seem to be a regex object. error.

Thanks in advance for any help.

Chris

import re

string = '''Love, Kenneth: 20
Chalkley, Andrew: 25
McFarland, Dave: 10
Kesten, Joy: 22
Stewart Pinchback, Pinckney Benton: 18'''


players = re.finditer(r'''
    ^(?P<first_name>[\w]+\s?[\w]+?)
    ,\s(?P<last_name>[\w]+\s?[\w]+?)
    :\s(?P<score>[\d]+)$
''', string, re.X | re.MULTILINE)


class Player:
    """Define the Player class."""

    def __init__(self, last_name=None, first_name=None, score=None):
        """Customize the class initiation."""
        for match in players:
            self.first_name = match.group('first_name')
            self.last_name = match.group('last_name')
            self.score = match.group('score')
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

Chris Guy, Don’t let the extra work Mark and I did confuse you. We went beyond the challenge to explore other capabilities of python.

You do not need to use finditer. You can stay with self or match. The re expression does not need to change in Task 2.

In the Player class, a loop is not needed. You can simply assign the attributes with the values passed in to the __init__ method. there is no need to reference the regex.

Post back if you need more help. Good luck!!!

Chris Guy
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Chris Guy
Python Web Development Techdegree Graduate 14,615 Points
Chris Guy
.a{fill-rule:evenodd;}techdegree seal-36
Chris Guy
Python Web Development Techdegree Graduate 14,615 Points

Hi Chris Freeman - thank you, this makes sense now!