Question 18

Question:

A website requires the users to input username and password to register. Write a program to check the validity of password input by users.

Following are the criteria for checking the password:

• At least 1 letter between [a-z]
• At least 1 number between [0-9]
• At least 1 letter between [A-Z]
• At least 1 character from [$#@]
• Minimum length of transaction password: 6
• Maximum length of transaction password: 12

Your program should accept a sequence of comma separated passwords and will check them according to the above criteria. Passwords that match the criteria are to be printed, each separated by a comma.

Example

If the following passwords are given as input to the program:

ABd1234@1,a F1#,2w3E*,2We3345

Then, the output of the program should be:

ABd1234@1

Hints:

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

Main author's Solution: Python 2

import re
value = []
items = [x for x in raw_input().split(',')]
for p in items:
    if len(p) < 6 or len(p) > 12:
        continue
    else:
        pass
    if not re.search("[a-z]",p):
        continue
    elif not re.search("[0-9]",p):
        continue
    elif not re.search("[A-Z]",p):
        continue
    elif not re.search("[$#@]",p):
        continue
    elif re.search("\s",p):
        continue
    else:
        pass
    value.append(p)
print ",".join(value)

My Solution: Python 3

def is_low(x):                  # Returns True  if the string has a lowercase
    for i in x:
        if 'a'<=i and i<='z':
            return True
    return  False

def is_up(x):                   # Returns True  if the string has a uppercase
    for i in x:
        if 'A'<= i and i<='Z':
            return True
    return  False

def is_num(x):                  # Returns True  if the string has a numeric digit
    for i in x:
        if '0'<=i and i<='9':
            return True
    return  False

def is_other(x):                # Returns True if the string has any "$#@"
    for i in x:
        if i=='$' or i=='#' or i=='@':
            return True
    return False

s = input().split(',')
lst = []

for i in s:
    length = len(i)
    if 6 <= length and length <= 12 and is_low(i) and is_up(i) and is_num(i) and is_other(i):   #Checks if all the requirments are fulfilled
        lst.append(i)

print(",".join(lst))

OR

def check(x):
    cnt = (6<=len(x) and len(x)<=12)
    for i in x:
        if i.isupper():
            cnt+=1
            break
    for i in x:
        if i.islower():
            cnt+=1
            break
    for i in x:
        if i.isnumeric():
            cnt+=1
            break
    for i in x:
        if i=='@' or i=='#'or i=='$':
            cnt+=1
            break
    return cnt == 5               # counting if total 5 all conditions are fulfilled then returns True

s = input().split(',')
lst = filter(check,s)             # Filter function pick the words from s, those returns True by check() function
print(",".join(lst))

OR

import  re

s = input().split(',')
lst = []

for i in s:
    cnt = 0
    cnt+=(6<=len(i) and len(i)<=12)
    cnt+=bool(re.search("[a-z]",i))      # here re module includes a function re.search() which returns the object information
    cnt+=bool(re.search("[A-Z]",i))      # of where the pattern string i is matched with any of the [a-z]/[A-z]/[0=9]/[@#$] characters
    cnt+=bool(re.search("[0-9]",i))      # if not a single match found then returns NONE which converts to False in boolean
    cnt+=bool(re.search("[@#$]",i))      # expression otherwise True if found any.
    if cnt == 5:
        lst.append(i)

print(",".join(lst))

'''Solution by: pratikb0501
'''
import re
a = input('Enter passwords: ').split(',')
pass_pattern = re.compile(r"^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[$#@]).{6,12}$")
for i in a:
    if pass_pattern.fullmatch(i):
        print(i)

OR

import re
def multiple (patterns, string):
  for i in patterns:
    if not re.search(i, string):
      return False
  
  if 6 <= len(string) <= 12:
    return True
  else:
    return False
x = str(input("Type password: "))
patterns = [r"[a-z]", r"[A-Z]", r"[0-9]", r"[$|#|@]"]
print(multiple(patterns, x))

Question 19

Question:

You are required to write a program to sort the (name, age, score) tuples by ascending order where name is string, age and score are numbers. The tuples are input by console. The sort criteria is:

• 1: Sort based on name
• 2: Then sort based on age
• 3: Then sort by score

The priority is that name > age > score.

If the following tuples are given as input to the program:

Tom,19,80
John,20,90
Jony,17,91
Jony,17,93
Json,21,85

Then, the output of the program should be:

[('John', '20', '90'), ('Jony', '17', '91'), ('Jony', '17', '93'), ('Json', '21', '85'), ('Tom', '19', '80')]

Hints:

In case of input data being supplied to the question, it should be assumed to be a console input.We use itemgetter to enable multiple sort keys.

Main author's Solution: Python 2

from operator import itemgetter, attrgetter

l = []
while True:
    s = raw_input()
    if not s:
        break
    l.append(tuple(s.split(",")))

print sorted(l, key=itemgetter(0,1,2))

My Solution: Python 3

lst = []
while True:
    s = input().split(',')
    if not s[0]:                          # breaks for blank input
        break
    lst.append(tuple(s))

lst.sort(key= lambda x:(x[0],int(x[1]),int(x[2])))  # here key is defined by lambda and the data is sorted by element priority 0>1>2 in accending order
print(lst)

Conclusion

Before the above problems, I didn't even know about re(regular expression) module and its use. I didn't even know how to sort by multiple keys. To solve those problems in different ways I had to explore and learn those syntax. There are a lots of interesting stuffs in re module though I faced quite a bit hardship to understand many of them.

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