Why is my Python code processing the header row in a CSV file instead of skipping it?

Skipping Headers When Processing a CSV File with Python

Problem:

In Python, a CSV file is being processed, but the first row (header row) is being modified instead of excluded.

Code in Question:

<code class="python">in_file = open("tmob_notcleaned.csv", "rb")
reader = csv.reader(in_file)
out_file = open("tmob_cleaned.csv", "wb")
writer = csv.writer(out_file)
row = 1

for row in reader:
    # Row processing logic

in_file.close()    
out_file.close()</code>

Issue:

Initializing the 'row' variable to 1 does not prevent the header row from being processed.

Solution:

To skip the header row, use the next() function to advance the reader iterable by one item. The return value of next() can be ignored in this case.

Modified Code:

<code class="python">with open("tmob_notcleaned.csv", "rb") as in_file, open("tmob_cleaned.csv", "wb") as out_file:
    reader = csv.reader(in_file)
    next(reader, None)  # Skip the header row
    writer = csv.writer(out_file)

    for row in reader:
        # Row processing logic</code>

Alternative Option:

If the header row is desired in the output file, it can be passed to writer.writerow() before the loop:

<code class="python">with open("tmob_notcleaned.csv", "rb") as in_file, open("tmob_cleaned.csv", "wb") as out_file:
    reader = csv.reader(in_file)
    headers = next(reader, None)  # Returns the header row or None if the input is empty

    if headers:
        writer.writerow(headers)

    for row in reader:
        # Row processing logic</code>

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