code: """
  Author : nkalyan🤠
  implementing Python Scripts on reading and returning the name no of mails that sent each day in week
   and plot/display them in bar graph
  
   I wrote code In  counting to count the number of emails sent by each distinct user.   That code may be helpful for this assignment.
  """
  
  
  import matplotlib.pyplot as plt
  from os import getcwd
  
  
  def file_path():
      """Method that ask the users file name and returns it"""
      file_name = input("Enter the file name:")
      return file_name
  
  
  def pop_values(filename):
      """Method the reads file and returning value"""
      file_name = filename
      try:                                    # look for exception
          fp = open(file_name, "r")
      except FileNotFoundError:               # if found exception display error
          print("File Does not exist, please check your file name")
          exit()
      else:                                   # if no exceptions thrown then performs this block
          with fp:
              for line in fp:
                  line = line.strip("\n")
                  offset = line.find("From")
                  offset1 = line.find("@")
                  line = line[-24:]
                  offset3 = line.find("@")
                  if offset == 0 and offset1 > 0 and offset3 == -1:
                      line = line[:-21]
                      yield line
  
  
  def main():
      """Calls the all functions that necessary to get the output"""
      name = file_path()      # calls the file path method
      dictionary = {'Sun': 0, 'Mon': 0, 'Tue': 0, 'Wed': 0, 'Thu': 0, 'Fri': 0, 'Sat': 0}  # store the day val in dict
      value = pop_values(name)
      count = 0
      for i in value:
          if i in dictionary:
              dictionary[i] += 1
          count += len(i)
      val = dictionary.values()
      keys = dictionary.keys()
      zp = zip(dictionary.keys(), dictionary.values())
      for item in val:
          i = val
          j = keys
          plt.bar(j, i, align='center', alpha=0.5)
  
      plt.ylabel('Number of messages')            
      plt.title('Emails per day')
      plt.show()                                  # method that shows the bar graph of our code result
  
  
  if __name__ == '__main__':
      """calls the main method"""
      main()
  
apis: matplotlib.pyplot.title matplotlib.pyplot.show matplotlib.pyplot.ylabel matplotlib.pyplot.bar