We use cookies to ensure you have the best browsing experience on our website. Please read our cookie policy for more information about how we use cookies.
  1. Prepare
  2. Python
  3. Regex and Parsing
  4. Validating Credit Card Numbers
  5. Discussions

Validating Credit Card Numbers

Sort by

recency

|

479 Discussions

|

  • singhshrajan
     + 0 comments
    1. def check(no):
    2. clean = no.replace("-", "")
    3. if len(clean)>16:
    4. return "Invalid"
    5. for i in range(len(clean) - 4):
    6. if clean[i] == clean[i+1] == clean[i+2] == clean[i+3]:
    7. return "Invalid"
    8. match = re.match(r"(([4-6]\d{3})(-?)\d{4}(-?)\d{4}(-?)\d{4})",no)
    9. if match:
    10. return "Valid"
    11. else:
    12. return "Invalid"
      1. for i in range(int(input())):
    14. print(check(input()))

  • a123s1l
     + 0 comments

    Here is my solution, wasted too much time to understand that i was not tracking "--", but fixed and it worked. ` import re

    n_cards = int(input()) if n_cards == 0: print()

    cards=[] for i in range(n_cards): cards.append(input().strip())

    pattern1 = r"^[456][0-9-]*$" # card format only digits or - pattern2 = r"(\d)\1{3,}" # 4 or more consecutive digits for card in cards: if len(card.replace("-","")) != 16: print("Invalid")
    else: # length is 16 without hyphens if bool(re.search(pattern1,card)) and not bool(re.search(pattern2,card.replace("-",""))): # if conditions match if "--" in card: print("Invalid") elif "-" in card: card_splits = any(a>4 for a in list(map(len,card.split("-")))) if card_splits:# if hyphen then groups of 4 numbers print("Invalid") # no invalid else:# yes valid print("Valid") else: print("Valid") else: print("Invalid")

  • deepadhyaa
     + 0 comments

    n=int(input()) a=[] for i in range(n): b=input() a.append(b) c=0 for i in a: if i[0] not in '456': c=c+1 if len(i)==16: for q in i: if q not in "0,1,2,3,4,5,6,7,8,9": c=c+1 if len(i)==19: for w in range(len(i)): if w in [4,8,12]: i[w]!="-" c=c+1 else: i[w]!="0,1,2,3,4,5,6,7,8,9" c=c+1 for k in range(0,len(i)-4): x=i[k] z=0 for l in range(k+1,k+5): if i[l]==x: z=z+1 if z>=3: c=c+1
    if c==0: print("Valid") else: print("Invalid")

  • prathamsavjani
     + 0 comments
    n = int(input())
acceptedCharacters = ['0','1','2','3','4','5','6','7','8','9','-']
for _ in range(n):
    countDigits = 0
    repeatCount = 1
    skip_outer = False
    card_number = input()
    if card_number[0] in ['4','5','6']:
        for char in card_number:
            if char in acceptedCharacters:
                if char != '-':
                    countDigits+=1
                continue
            else:
                skip_outer = True
        if skip_outer == True:
            print('Invalid')
            continue
        if countDigits != 16:
            print('Invalid')
            continue
        if '-' in card_number:
            temp_list = card_number.split('-')
            for item in temp_list:
                if len(item) == 4:
                    continue
                else:
                    skip_outer = True
                    break
            if skip_outer == True:
                print('Invalid')
                continue
            card_number = "".join(temp_list)
            
        for i in range(0,len(card_number)-1): 
            if card_number[i] == card_number[i+1]:
                repeatCount += 1
                if repeatCount == 4:
                    skip_outer = True
                    break
            else:
                repeatCount = 1
        if skip_outer == True:
                print('Invalid')
                continue
    else:
        print('Invalid')
        continue
    print('Valid')

  • ishanstealth18
     + 0 comments
    t = int(input())
p1 = r'^[456]'
p2 = r'^.{16,19}$'
p3 = r'\d{4}-\d{4}-\d{4}-\d{4}'
p4 = r'[^@_!#$%^&*()<>?/\|}{~:]'
p5 = r'(\d)(-\1+)'
p6 = r'(\d)\1{3,}'

for i in range(t):
    number = input()
    c1 = re.match(p1,number) 
    c2 = re.match(p2,number)
    c3= re.search(p3,number)
    c4 = re.match(p4,number)
    c5 = re.search(p5,number)
    c6 = re.search(p6,number)
    #print(c1,c2,c3,c4,c5,c6)
    if '-' in number:
        if c1 != None and c2 != None and c3 != None and c4 != None and c6 == None and c5 == None:
            print('Valid')
        else:
            print('Invalid')
    else:
        if c1 != None and c2 != None and c4 != None:
            print('Valid')
        else:
            print('Invalid')