Question

Python 3.1 - 3.5

Certain machine parts are assigned serial numbers. Valid serial numbers are of the form: SN/nnnn-nnn where ‘n’ represents a digit. Write a function valid_sn that takes a string as a parameter and returns True if the serial number is valid and False otherwise.

For example, the input "SN/5467-231" returns True "SN5467-231" returns False

"SN/5467-2231" returns False

Using this function, write and test another function valid-sn-file that takes three file handles as input parameters. The first handle is to the file contains a list of serial numbers, the second and third are to output files. Write all valid serial numbers to the second file handle and invalid serial numbers to the third.

txt file:

Boston Americans
New York Giants
Chicago White Sox
Chicago Cubs
Chicago Cubs
Pittsburgh Pirates
Philadelphia Athletics
Philadelphia Athletics
Boston Red Sox
Philadelphia Athletics
Boston Braves
Boston Red Sox
Boston Red Sox
Chicago White Sox
Boston Red Sox
Cincinnati Reds
Cleveland Indians
New York Giants
New York Giants
New York Yankees
Washington Senators
Pittsburgh Pirates
St. Louis Cardinals
New York Yankees
New York Yankees
Philadelphia Athletics
Philadelphia Athletics
St. Louis Cardinals
New York Yankees
New York Giants
St. Louis Cardinals
Detroit Tigers
New York Yankees
New York Yankees
New York Yankees
New York Yankees
Cincinnati Reds
New York Yankees
St. Louis Cardinals
New York Yankees
St. Louis Cardinals
Detroit Tigers
St. Louis Cardinals
New York Yankees
Cleveland Indians
New York Yankees
New York Yankees
New York Yankees
New York Yankees
New York Yankees
New York Giants
Brooklyn Dodgers
New York Yankees
Milwaukee Braves
New York Yankees
Los Angeles Dodgers
Pittsburgh Pirates
New York Yankees
New York Yankees
Los Angeles Dodgers
St. Louis Cardinals
Los Angeles Dodgers
Baltimore Orioles
St. Louis Cardinals
Detroit Tigers
New York Mets
Baltimore Orioles
Pittsburgh Pirates
Oakland Athletics
Oakland Athletics
Oakland Athletics
Cincinnati Reds
Cincinnati Reds
New York Yankees
New York Yankees
Pittsburgh Pirates
Philadelphia Phillies
Los Angeles Dodgers
St. Louis Cardinals
Baltimore Orioles
Detroit Tigers
Kansas City Royals
New York Mets
Minnesota Twins
Los Angeles Dodgers
Oakland Athletics
Cincinnati Reds
Minnesota Twins
Toronto Blue Jays
Toronto Blue Jays
Atlanta Braves
New York Yankees
Florida Marlins
New York Yankees
New York Yankees
New York Yankees
Arizona Diamondbacks
Anaheim Angels
Florida Marlins
Boston Red Sox
Chicago White Sox
St. Louis Cardinals
Boston Red Sox
Philadelphia Phillies

Answer 1

Python Code:

Function: valid_sn

def valid_sn(serialNo):
   """
       Function that validates the Serial Number of form SN/nnnn-nnn
   """
   # Validating Length
   if len(serialNo) != 11:
       return False;
      
   # Checking for String , / and - in correct positions  
   if serialNo[:2] != "SN" or serialNo[2] != '/' or serialNo[7] != '-':
       return False;
  
   # Extracting sub-strings nnnn
   nnnn = serialNo[3:7];

   # Extracting sub-strings nnn
   nnn = serialNo[8:];
  
   # Checking that all characters in nnnn are digits
   for ch in nnnn:
       if not ch.isdigit():
           return False;
  
   # Checking that all characters in nnn are digits  
   for ch in nnn:
       if not ch.isdigit():
           return False;
  
   # All conditions satisfied, return True
   return True;
   

Sample Run:

Python 3.5.2 Shell File Edit Shell Debug Options Window Help 37 def valid sn(serialNo) Function that validates the Serial Number of form SN/nnnn-nnn # Validating Length if len serialNo) !-11: return False: # Checking for String , / and- in correct positions if serialNo[ :2 ] !-"SN" or serialNo [2] != '/' or seria!No [7] .- '-' return Falsei # Extracting sub-strings nnnn seria!No(3:71; nnnn # Extracting sub-strings nnn # Checking that all characters in nnnn are digits for ch in nnnn if not ch.isdigit ): return False,i # Checking that all characters in nnn are digits for ch in nnn if not ch.isdigit): return Falsei # All conditions satisfied, return True return True: 3> valid sn("SN/5467 231" True >3 valid sn"SN5467-231") False valid sn"SN/5467-2231 False 7

_____________________________________________________________________________________________

Function: valid_sn_file

def valid_sn_file(ipFile, validSerialNoFile, invalidSerialNoFile):
   """
       First handle is to the file contains a list of serial numbers, the second and third are to output files
       Write all valid serial numbers to the second file handle and invalid serial numbers to the third
   """
  
   try:
       # Extracting data from file
       for serialNo in ipFile:
           # Stripping white spaces
           serialNo = serialNo.strip(" \n");
           # Validating serial number
           if valid_sn(serialNo):
               # Valid serial number - Writing to second file
               validSerialNoFile.write(serialNo);
               validSerialNoFile.write("\n");
           else:
               # InValid serial number - Writing to second file
               invalidSerialNoFile.write(serialNo);
               invalidSerialNoFile.write("\n");
      
       # Closing files
       ipFile.close();
       validSerialNoFile.close();
       invalidSerialNoFile.close();
      
       print("\n Data has been processed successfully.. Written to output files... \n");
      
   except Exception as ex:
       # Handling Exceptions
       print(ex);

Sample Run:

Python 3.5.2 Shell File Edit Shell Window serialNum.txt - Notepd File Edit Format View sss def valid an file(ipFile, validSerialNoFile, invalidserialNoFile): SN/5467-231 SN5467-231 SN/2258-125 SN//467-231 SN/8975-3-1 Eirst handle is t the file contain a list of serial numbers, the second and third are to output files ry: # Extracting data from file # Stripping white spaces erialNoserialNo.strip # Validating erial number validSerialNumtxt File Edit Format View Help SN/5467-231 # Valid erial number-ห1ìtǐng t val idSerialNoEile . write (aeria!No: validserialNoFile.write("n" =econd file SN/2258-125 else: # Invalid霋erial number -Wr ting to second file invalidSeriaiNoFile.write (serialNo invalidSerialNoFile.write(n" # Closing files ipFile.closa) validserialNoFile.close invalidSerialNoFile.close) invalidSerialNum.txt- Not.. File Edit Format View Help SN5467-231 SN//467-231 SN/8975-3-1 printrn Date has been processed successfully. Written to output files. n" except Exception as ex # Handling Exceptions print (ex)i >>> ipE11e = open("seriainun.txt"."z"); ss validFilel-open"validSerialNum.sxt invalidF1leopen"invalidserialNum.txt", s>> valid an file (ipFile, validFilel, invalidFile) Ln: 321 Col: 4 u UTF-R