How to Skip Headers When Processing CSV Files with Python?

Skipping Headers When Processing CSV Files with Python

Problem:

When attempting to process a CSV file using Python, the user encounters an issue where the first row, containing the headers, is being modified by the processing functions. The goal is to edit the CSV file starting from the second row, excluding the headers.

Solution:

To resolve this issue, the csv.reader object provided by the Python CSV module can be employed to skip the headers during the processing. The following steps outline the solution:

1. Open the CSV Files as Context Managers:

   <code class="python">with open("tmob_notcleaned.csv", "rb") as in_file, open("tmob_cleaned.csv", "wb") as out_file:</code>

   Using with as a context manager automatically handles the opening and closing of the CSV files, ensuring proper resource management.

2. Create the Reader and Writer Objects:

   <code class="python">reader = csv.reader(in_file)
   writer = csv.writer(out_file)</code>

   The csv.reader creates an iterable object to iterate through the CSV rows, while csv.writer allows writing rows to the output CSV file.

3. Skip the Headers:

   <code class="python">next(reader, None)</code>

   This line advances the iterator to the first row without assigning it to a variable. By providing None as the second argument, the skipped row is discarded.

4. Process and Write the Remaining Rows:

   <code class="python">for row in reader:
       # Perform processing
       writer.writerow(row)</code>

   Iterate through the remaining rows, excluding the headers, perform the necessary processing, and write the modified rows to the output file.

5. Optionally Write the Headers (if desired):

   <code class="python">headers = next(reader, None)
   if headers:
       writer.writerow(headers)</code>

   This block of code allows writing the headers to the output file unprocessed by passing the result of next() to writer.writerow().

By following these steps, the Python code will skip the headers when processing the CSV file, ensuring that the first row remains unmodified.

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