Use the information below to write a python script to match phone numbers. Also est your program on a sample search string containing a phone number. Information: Say you want to find a phone number in a string. You know the pattern: three numbers, a hyphen, three numbers, a hyphen, and four numbers. Here’s an example: 415-555-4242. Let’s use a function named isPhoneNumber() to check whether a string matches this pattern, returning either True or False. Open a new file editor window and save the file as isPhoneNumber.py. Regular expressions, called regexes for short, are descriptions for a pattern of text. For example, a \d in a regex stands for a digit character—that is, any single numeral 0 to 9. The regex \d\d\d-\d\d\d- \d\d\d\d is used by Python to match the text containing phone numbers in the isPhoneNumber() function: a string of three numbers, a hyphen, three more numbers, another hyphen, and four numbers. Any other string would not match the \d\d\d-\d\d\d-\d\d \d\d regex. But regular expressions can be much more sophisticated. For example, adding a 3 in curly brackets ({3}) after a pattern is like saying, “Match this pattern three times.” So the slightly shorter regex \d{3}-\d{3}-\d{4} also matches the correct phone number format. All the regex functions in Python are in the re module. Enter the following into an interactive shell to import this module: A Regex object’s search() method searches the string it is passed for any matches to the regex. The search() method will return None if the regex pattern is not found in the string. If the pattern is found, the search() method returns a Match object. Match objects have a group() method that will return the actual matched text from the searched string.
Use the information below to write a python script to match phone numbers. Also est your
program on a sample search string containing a phone number.
Information:
Say you want to find a phone number in a string. You know the pattern: three numbers, a hyphen,
three numbers, a hyphen, and four numbers. Here’s an example: 415-555-4242.
Let’s use a function named isPhoneNumber() to check whether a string matches this pattern,
returning either True or False. Open a new file editor window and save the file as
isPhoneNumber.py.
Regular expressions, called regexes for short, are descriptions for a pattern of text. For example, a
\d in a regex stands for a digit character—that is, any single numeral 0 to 9. The regex \d\d\d-\d\d\d-
\d\d\d\d is used by Python to match the text containing phone numbers in the isPhoneNumber()
function: a string of three numbers, a hyphen, three more numbers, another hyphen, and four
numbers. Any other string would not match the \d\d\d-\d\d\d-\d\d
\d\d regex. But regular expressions can be much more sophisticated. For example, adding a 3 in
curly brackets ({3}) after a pattern is like saying, “Match this pattern three times.” So the slightly
shorter regex \d{3}-\d{3}-\d{4} also matches the correct phone number format.
All the regex functions in Python are in the re module. Enter the following into an interactive shell
to import this module:
A Regex object’s search() method searches the string it is passed for any matches to the regex. The
search() method will return None if the regex pattern is not found in the string. If the pattern is
found, the search() method returns a Match object. Match objects have a group() method that will
return the actual matched text from the searched string.
In below script, we define a function isPhoneNumber() which takes a string as input and returns True if the string matches the phone number pattern (three numbers, a hyphen, three numbers, a hyphen, and four numbers), and False otherwise.
We first compile a regular expression pattern using the re.compile() function, which creates a Regex object. The pattern \d{3}-\d{3}-\d{4} matches the phone number pattern we're looking for.
We then use the search() method of the Regex object to search for matches of the pattern in the input string. If a match is found, the search() method returns a Match object, which we can check for truthiness. If there is a match, we return True, and if not, we return False.
Finally, we test the function by looping over substrings of the input string and calling the isPhoneNumber() function on each substring. If a phone number is found, we print a message indicating that a phone number was found.
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