Question

python 3

8.12 LAB: Python cross reference In addition to editors and compilers, a software developer may use tools to analyze the software they are writing to examine the names being used for variables and functions, and list the line numbers where the variables and functions names appear. For example, consider the following program savings.py used to compute the month to month interest gained from a certificate of deposit: 1: Input the CD APR, no years and initial deposit 2: apr = float (input("Enter the APR for the CD: \n")) / 100 3: no_years - int (input ("Enter the number of years: \n")) 4: balance - float (input ("Enter initial deposit: \n")) 5: 6: + Calculate monthly percentage rate 7: mpr - apr / 12 8: 9: print() 10: 11: Print the investment schedule 12: for year in range (1, no_years + 1) : 13: print("Year(): .format(year) 14: print() 15: print(" Month Balance") 16: print(" ") 17: for month in range (1, 13): 18: balance + mpr. balance 19: print [:20) $ : 8.2f)'.format (month, balance)) 20: print) 21: print('Balance end of year () is $ {: .2E)'.format(year, balance) 22: print)

Answer 1

'''
Python version : 3.6
Python program to input a filename of python source and print a cross
reference of the python names found within the source file.
'''

def get_python_names(line):
   ''' Get a set of python names found within a line '''
  
   found_names = set()
   python_name = ""
   quote = None
  
   for c in line:
       if quote:
           if c == quote:
               quote = None
           continue

       if c == '"' or c == "'":
           quote = c
           continue
      
       if c == '#':
           break
          
       if c.isalpha() or c == '_' or (len(python_name) > 0 and c.isdigit()):
           python_name += c
       elif len(python_name) > 0:
           found_names.add(python_name)
           python_name = ""
      
   if len(python_name) > 0:
       found_names.add(python_name)
      
   return found_names

if __name__ == "__main__":
  
   # create a dictionary, with keys be the names and values be the list of line numbers where it is found
   cross_reference_dict = {}  
   # input the filename
   filename = input('Enter the filename: ')
  
   # open the file in read mode
   file = open(filename)
   line_no = 1 # set line_no to start line
   # read a line from file
   line = file.readline()
   # loop till the end of file
   while line:
       # get the names from the line
       found_names = get_python_names(line)
       # loo pover the names and add it to cross_reference_dict
       for name in found_names:
           # name present in dictionary, append the line_no to the list
           if name in cross_reference_dict:
               cross_reference_dict[name].append(line_no)
           else: # name not found in dictionary, create a new record with list containing the line_no
               cross_reference_dict[name] = [line_no]
      
       line_no += 1 # increment the line number
       # read the next line
       line = file.readline()
      
   # get the keys from the dictionary
   names = cross_reference_dict.keys()
   names.sort() # sort the names in ascending order
  
   # loop over the sorted names, to display the name and the line numbers
   for name in names:
       # display the name
       print('%-20s'%(name), end='')
       # get the list of line numbers
       line_nums = cross_reference_dict[name]
       # loop over the line numbers, to display them
       for i in range(len(line_nums)-1):
           print('%d, '%(line_nums[i]), end='')
       print(line_nums[len(line_nums)-1])

#end of program      

Code Screenshot:

IT 1 2 3 Python version: 3.6 Python program to input a filename of python source and print a cross reference of the python names found within the source file. 4 וויL def get_python_names (line): Get a set of python names found within a line !!! found_names = set() python_name = quote = None 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 for c in line: if quote: if c = quote: quote = None continue == HTT TI I TI if c == or c quote = c continue 23 if c == '#': break 1 DID 24 25 26 27 28 29 30 31 32 33 34 35 36 37 if c.isalpha () or c == or (len (python_name) > 0 and c.isdigit()): python_name += c elif len (python_name) > 0: found_names.add (python_name) python_name = if len (python_name) > 0: found_names.add (python_name) return found names

T! Elif name == main # create a dictionary, with keys be the names and values be the list of line numbers where it is found cross_reference dict = {} # input the filename filename = input ("Enter the filename: ') 38 39 40 41 42. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 # open the file in read mode file = open(filename) line_no = 1 # set line no to start line # read a line from file line = file.readline () # loop till the end of file while line: # get the names from the line found_names = get_python_names (line) # loopover the names and add it to cross reference dict for name in found_names: # name present in dictionary, append the line_no to the list if name in cross_reference_dict: cross_reference_dict[name].append (line_no) else: # name not found in dictionary, create a new record with list containing the line_no cross_reference_dict[name] = [line_no] line_no += 1 # increment the line number # read the next line line = file.readline () 64 65 66 67 # get the keys from the dictionary names = cross_reference_dict.keys () names.sort() # sort the names in ascending order 68 69 70 71 72 73 74 75 76 77 78 79 80 81 # loop over the sorted names, to display the name and the line numbers for name in names: # display the name print(" %-20 s'$ (name), end='') # get the list of line numbers line nums = cross_reference dict[name] # loop over the line numbers, to display them for i in range (len (line nums)-1): print('%d, '$(line_nums[i]), end='') print(line_nums[len(line_nums)-1]) #end of program

Output:

Input file:

# Input the CD APR, no years and initial deposit apr = float(input ("Enter the APR for the CD: \n")) no_years = int(input ("Enter the number of years: \n")) balance = float (input ("Enter initial deposit: \n")) # Calculate monthly percentage rate mpr = apr/12 print() 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 # print the investment schedule Çfor year in range(1, no_years+1): print("Year :'.format(year)) print() print(" Month Balance") print(" ") for month in range (1,13): balance += mpr * balance print {:20] ${:8.2f}'.format (month, balance)) print() print('Balance end of year {} is $ {: .2f}'. format (year, balance)) print()

Output:

Enter the filename: savings.py apr 2, 7 balance 4, 18, 19, 21 float 2, 4 for 12, 17 format 13, 19, 21 in 12, 17 input 2, 3, 4 int 3 month 17, 19 mpr 7, 18 no years 3, 12 print 9, 13, 14, 15, 16, range 12, 17 year 12, 13, 21 19, 20, 21, 22