Open and Read a file in Python

Below is an example code which reads “file.csv”. Assume it contains data from a table with table headers as it’s first row.

We extract the table header with : contents_header = contents[0]
We then remove the table header from dataset by slicing: contents = contents[1:]

Function explore_data() prints rows read from file. It can also show total no. of rows and columns in the data.

from csv import reader

opened_file = open('file.csv')
read_file = reader(opened_file)
contents = list(read_file)   #read the contents of file as a list
contents_header = contents[0] #extract only the header
contents = contents[1:]      #remove the header

def explore_data(dataset, start, end, rows_and_columns=False):
    dataset_slice = dataset[start:end]    
    for row in dataset_slice:
        print(row)
        print('\n') # adds a new (empty) line between rows
        
    if rows_and_columns:
        print('Number of rows:', len(dataset))
        print('Number of columns:', len(dataset[0]))

print('Header : \n', contents_header)
print('\n')
explore_data(contents, 0, 3, True)  #print row 0 to 2, Also show no. of rows and columns

Example: