本文实例为大家分享了python使用正则筛选信用卡的具体代码，供大家参考，具体内容如下

本文来源于两个简单的题目：

1.判断一对单词是否是" Anagrams "
2.判断信用卡是否合理

判断 Anagramsstrong>

anagrams 的百度翻译：由颠倒字母顺序而构成的字（短语）

而题目给出例子：

[ DOG , ODG ]
[ DOG , DOG ]
[ DOG , GOD ]
[ DOG , GDO ]

均为 anagrams 。

那思路就简单了，直接拆分字母，排序，比较就 ok 。

判断信用卡

题目给出的要求如下：

The criteria are:
• It must start with a 4,5 or 6
• It must be exactly 16 digits
• It must be numbers only
• It can have a digits in groups of 4, separated by one hyphen “-“
• It should not contain any other characters.
• It must NOT have any 4 repeated digits.

样例输出如下：

378282246310005 Invalid
30569309025904 Invalid
6011111111111117 Invalid
5123-2332-3232-3213 valid

py文件

两个题目合并在一个 py 文件中。　
而入参数分别是两个文件的名字，一个是 anagram.txt ，另一个是 credit_cards.txt ，他们分别长这样：

最后的程序长这样：

#! /usr/bin/python3import re#################################You need to implet the following methods:####Question 1##anagram_validator() ####Question 2##credit_card_validator() #################################################################################### Question 1: Check for anagrams:####################################################def get_list(src_str): sub_list=[] word_tmp='' for word in src_str: if word != ',': word_tmp = word_tmp+word else: sub_list.append(word_tmp) word_tmp = '' return sub_listdef read_anagram(file_name): ''' Input: a file name Return: a nested list of two words list Example : [[word1,word2],[word3,word4]...etc] ''' with open(file_name,encoding = 'utf-8') as f: return_list =[] file_conment = f.read() file_conment_new = re.sub(r'\n',',',file_conment) file_conment_new = file_conment_new+',' subs_list = get_list(file_conment_new) i=0 while i < (len(subs_list)-1): return_list.append([subs_list[i],subs_list[i+1]]) i=i+2 return return_listdef anagram_validator(anagram): ''' Input is the output from "read_anagram()". Return: list of "anagrams" or "Not anagrams" values for each two words example input (dog,gdo),(try,elm) then output would be ["anagrams","Not anagrams"] with sequence of the input ''' result_list=[] for i in range(len(anagram)): word_font = ''.join((lambda x:(x.sort(),x)[1])(list(anagram[i][0]))) word_back = ''.join((lambda x:(x.sort(),x)[1])(list(anagram[i][1]))) if word_font == word_back: result_list.append('Anagrams') else: result_list.append('Not anagrams') return result_list############################################# Question 2: Validate credit cards #############################################def read_credit_cards(file_name): ''' Input: a file name Return tuple of numbers ''' with open(file_name,encoding='utf-8') as f: card_conment = f.read() card_conment = re.sub(r'\[','',card_conment) card_conment = re.sub(r'\]','',card_conment) card_conment = card_conment+',' card_list = get_list(card_conment) return tuple(card_list)def credit_card_validator(numbers): ''' Input: tuple of numbers Return:dictionary of credit card numbers where key is the number and value if valid or invalid ''' validator_list=[] credit_dict={} for i in range(len(numbers)): validator_list.append(numbers[i]) for i in range(len(numbers)): ch_num = 0 repeat_flag = 0 for ch in validator_list[i]: if ord("A")<=ord(ch)<=ord("Z"): ch_num+=1 break tmp_list = [] tmp_list = (re.sub(r"[^\d]", "", validator_list[i])) for index in range(len(tmp_list)-4): if(tmp_list[index] == tmp_list[index+1] and tmp_list[index] == tmp_list[index+2] and tmp_list[index] == tmp_list[index+3] ): repeat_flag = 1 break; if(validator_list[i][0] != '4' and validator_list[i][0] != '5' and validator_list[i][0] != '6' ): credit_dict[validator_list[i]]='Invalid' elif( len(re.sub(r"\D", "", validator_list[i])) != 16 ): credit_dict[validator_list[i]]='Invalid' elif(ch_num > 0): credit_dict[validator_list[i]]='Invalid' elif( (re.search(r"-",validator_list[i])) and ( validator_list[i][4] != '-' or validator_list[i][9] != '-'or validator_list[i][14] != '-' ) ): credit_dict[validator_list[i]]='Invalid' elif(re.search(r"[^-\d]",validator_list[i])): credit_dict[validator_list[i]]='Invalid' elif(repeat_flag == 1 ): credit_dict[validator_list[i]]='Invalid' else : credit_dict[validator_list[i]]='Valid' space_str = '' return credit_dictdef print_credit_card_summary(dict_o): ''' Input: dict Return: printing summary of validation result - space between credit card and status is 40 width example: 378282246310005 Invalid 30569309025904 Invalid ''' space_str = '' for key in dict_o: new_str = key + dict_o[key] if(dict_o[key] == "Valid"): new_str_tmp = new_str[:-5] space_lenth = 46-len(new_str) for x in range(space_lenth): space_str +=' ' print(new_str_tmp + space_str + 'Valid') space_str='' else : new_str_tmp = new_str[:-7] space_lenth = 48-len(new_str) for x in range(space_lenth): space_str +=' ' print(new_str_tmp + space_str + 'Invalid') space_str='' ####### THE CODE BELOW IS FOR TESTING################################## DO NOT CHANGE #########################import sysif __name__ == '__main__': # Take care of the console inputs if len(sys.argv) <= 1: sys.argv = ['', "anagram.txt", "credit_cards.txt"] stars = '*' * 40 print(stars) print("Testing Question 1 --- Anagrams?") print(stars) # testing reading_anagrams try: anagram = read_anagram(sys.argv[1]) if not anagram: print("read_anagram() returns None.") else: print("anagram: ", anagram) print() except Exception as e: print("Error (readnumbers()): ", e) # testing anagram_validator Anagrams = 0 NAnagrams = 0 try: if not anagram: # Question 1 has not been implemented print("anagram_validator() skipped....") else: result = anagram_validator(anagram) if result == None: print("anagram_validator() returns None.") else: for i in result: if i == "Anagrams": Anagrams += 1 elif i == "Not anagrams": NAnagrams += 1 print("Number of valid Anagrams is {} and Not anagrams is {}.".format(Anagrams, NAnagrams)) except Exception as e: print("Error (anagram_validator()):", e) # testing Question 2 print("\n\n" + stars) print("Testing Question 2 --- Credit Card Validator") print(stars) # Testing reading_credit_cards try: tup = read_credit_cards(sys.argv[2]) if not tup: print("read_credit_cards() returns None.") else: print("The tuple of credit_cards: {}".format(tup)) except Exception as e: print("Error (read_credit_cards()):", e) # Testing credit_card_validator vcc = 0 ivcc = 0 try: if not tup: # Readin_Question 2 has not been implemented print("credit_card_validator() skipped...") else: cc_dict = credit_card_validator(tup) tmp_cc_dict = cc_dict if not cc_dict: print("credit_card_validator() returns None.") else: for items in cc_dict.keys(): if cc_dict[items] == "Valid": vcc += 1 elif cc_dict[items] == "Invalid": ivcc += 1 print("Number of valid credit cards is {} and invalid {}.".format(vcc, ivcc)) except Exception as e: print("Error (credit_card_validator()):", e) # testing Question 2 print("\n\n" + stars) print("Testing Question 2b --- Print Credit Card Summary") print(stars) # Testing print_credit_card_summary try: if not tmp_cc_dict: # Dict credit card output has not been implemented print("print_credit_card_summary() skipped...") else: import io # do not delete this line from contextlib import redirect_stdout # do not delete this line f = io.StringIO() with redirect_stdout(f): print_credit_card_summary(tmp_cc_dict) out = f.getvalue() if not out: print("print_credit_card_summary() returns None.") else: count44 = 0 count46 = 0 for line in out.splitlines(): if len(line) - len(line.split()) == 44: count44 += 1 elif len(line) - len(line.split()) == 46: count46 += 1 if count44 == vcc and count46 == ivcc: print("Your format looks good") else: print("You might have some issues in your summary format") except Exception as e: print("Error (print_credit_card_summary()):", e)

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。