Day_14.md

Question 51

Question

Write a function to compute 5/0 and use try/except to catch the exceptions.

---

Hints

Use try/except to catch exceptions.

---

Main author's Solution: Python 2

def throws():
    return 5/0

try:
    throws()
except ZeroDivisionError:
    print "division by zero!"
except Exception, err:
    print 'Caught an exception'
finally:
    print 'In finally block for cleanup'

---

My Solution: Python 3

def divide():
    return 5/0

try:
    divide()
except ZeroDivisionError as ze:
    print("Why on earth you are dividing a number by ZERO!!")
except:
    print("Any other exception")

---

Question 52

Question

Define a custom exception class which takes a string message as attribute.

---

Hints

To define a custom exception, we need to define a class inherited from Exception.

---

Main author's Solution: Python 2

class MyError(Exception):
    """My own exception class

    Attributes:
        msg  -- explanation of the error
    """

    def __init__(self, msg):
        self.msg = msg

error = MyError("something wrong")

---

My Solution: Python 3

class CustomException(Exception):
    """Exception raised for custom purpose

    Attributes:
        message -- explanation of the error
    """

    def __init__(self, message):
        self.message = message


num = int(input())

try:
    if num < 10:
        raise CustomException("Input is less than 10")
    elif num > 10:
        raise CustomException("Input is grater than 10")
except CustomException as ce:
    print("The error raised: " + ce.message)

---

Question 53

Question

Assuming that we have some email addresses in the "username@companyname.com" format, please write program to print the user name of a given email address. Both user names and company names are composed of letters only.

Example: If the following email address is given as input to the program:

john@google.com

Then, the output of the program should be:

john

In case of input data being supplied to the question, it should be assumed to be a console input.

---

Hints

Use \w to match letters.

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Main author's Solution: Python 2

import re
emailAddress = raw_input()
pat2 = "(\w+)@((\w+\.)+(com))"
r2 = re.match(pat2,emailAddress)
print r2.group(1)

---

My Solution: Python 3

email = "john@google.com"
email = email.split('@')
print(email[0])

---

OR

import re

email = "john@google.com elise@python.com"
pattern = "(\w+)@\w+.com"
ans = re.findall(pattern,email)
print(ans)

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