Python CSV dictReader，没有得到预期 output

Question

Below is the code, opening the file and passing it to CSV handler in python

def csv_reader_dict():
  #Reading Data From CSV file into Dictionary using csv
  print("---------Reading Data From CSV file into Dictionary using csv------------")
  with open('input.txt','r') as file_data:
    csv_format = csv.DictReader(file_data)
    line_count2 = 0
    for row in csv_format:
        if line_count2 == 0:
            print("Header are {}".format(",".join(row) ))
            line_count2 += 1
        else:
            print("{} reside at {} and joined on {}".format(row["name"],row["address"],row["date joined"]))
            line_count2 += 1
    print("Processed {} line count".format(line_count2))
  print("------------------------------------------------------------------------")
  print("\n")

csv_reader_dict()

Expected Output:

Actual Output:

Answer 1

DictReader assumes the first row to be headers so it skips it. In your code you are using your first iteration to print headers and not the required information.

Adding fieldnames to DictReader should work because it will not skip the first row and your code will work as intended.

def csv_reader_dict():
#Reading Data From CSV file into Dictionary using csv
print("---------Reading Data From CSV file into Dictionary using csv------------")
with open('input.txt','r') as file_data:
    csv_format = csv.DictReader(file_data, fieldnames=['name', 'address', 'date joined'])
    line_count2 = 0
    for row in csv_format:
        if line_count2 == 0:
            print("Header are {}".format(",".join(row) ))
            line_count2 += 1
        else:
            print("{} reside at {} and joined on {}".format(row["name"],row["address"],row["date joined"]))
            line_count2 += 1
    print("Processed {} line count".format(line_count2))
print("------------------------------------------------------------------------")
print("\n")

Answer 2

When line_count2 == 0 it's iterating through the first row (john smith), and you are forcing when line_count2 == 0 to print the header.

You think that the line print("Header are {}".format(",".join(row) )) it's printing the header, but it's printing the keys of the first row, that are the same headers.

You can simplify the function:

def csv_reader_dict():
    #Reading Data From CSV file into Dictionary using csv
    print("---------Reading Data From CSV file into Dictionary using csv------------")
    with open('input.txt','r') as file_data:
        csv_format = csv.DictReader(file_data)
        line_count2 = 0
        print("Header are {}".format(",".join(csv_format.fieldnames)))
        for row in csv_format:
            print("{} reside at {} and joined on {}".format(row["name"],row["address"],row["date joined"]))
            line_count2 += 1
    print("Processed {} line count".format(line_count2))
    print("------------------------------------------------------------------------")
    print("\n")

csv_reader_dict()