how to fix value error in python code example

Example 1: how to fix valueerror in python

#Instead of
a = int(input("What is x?"))
#Put
try:
  	a = int(input("What is x?"))
except ValueError:
  print ("Insert ValueError message here")
#This way your program won't crash

Example 2: how to fix value error in python

def example():
  i = 0
  resultlist_key = []
  result_list = list()
  a_list = list()
  b_list = list()
  a_list.append(feature_matrix_ip)# feature_matrix_ip contains features of the query image
  while i < 70:
      b_list.append(feature_matrix_db[i])# feature_matrix_db contains features of img. in DB
      dist = distance.euclidean(a_list,b_list[i])
      result_list.append(dist)
      resultlist_key = OrderedDict(sorted(enumerate(result_list),key=lambda x: x[0])).keys()
      i = i + 1 
      res_lst_srt = {'values': result_list,'keys':resultlist_key}
      res_lst_srt['values'], res_lst_srt['keys'] = zip(*sorted(zip(res_lst_srt['values'], res_lst_srt['keys'])))# sorting according to the least distance and the key will not change
      key = res_lst_srt['keys']

Example 3: how to fixvalue error in python

filename = "language.txt"
#open file for writing
fileHandler = open (filename, "w")

#Add some text
fileHandler.write("Bash\n")
fileHandler.write("Python\n")
fileHandler.write("PHP\n")

#close the file
fileHandler.close()

#open file the  file and read the data

filehandler = open(filename, "r")

#Read the  file by line

for line in fileHandler:
    print(line)

#close the  file
fileHandler.close()