Writing to CSV files
You can write data to a CSV file with the writer object in the csv module.
You can use the writerows() method which takes multiple rows in one go.
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import csv
data = [["name", "faculty", "department"], ["Davies", "Eng", "EEE"],
["Smith", "Eng", "Computing"]]
with open("uni.csv", "w") as csv_file:
writer = csv.writer(csv_file)
writer.writerows(data)
The content of the new uni.csv should look like this:
name,faculty,department
Davies,Eng,EEE
Smith,Eng,Computing
You can also add a new (single) row to the CSV we generated using the .writerow() method.
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import csv
row = ["Williams", "Eng", "EEE"]
# Note append mode "a". We are appending new items to an existing file
with open("uni.csv", "a") as csv_file:
writer = csv.writer(csv_file)
writer.writerow(row)
The content of uni.csv now looks like this:
name,faculty,department
Davies,Eng,EEE
Smith,Eng,Computing
Williams,Eng,EEE
Writing to CSV files from a dictionary
You can also write to a CSV file from a dictionary.
Writing row by row (this piece of code demonstrates a CSV separated by |):
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import csv
with open("uni.csv", "w") as csv_file:
fieldnames = ["name", "faculty", "dept"]
writer = csv.DictWriter(csv_file, fieldnames=fieldnames, delimiter="|")
writer.writeheader()
writer.writerow({"name": "Davies", "faculty": "Eng", "dept": "EEE"})
writer.writerow({"name": "Smith", "faculty": "Eng", "dept": "Computing"})
The output uni.csv file is:
name|faculty|dept
Davies|Eng|EEE
Smith|Eng|Computing
You can also dump a whole dictionary into a CSV file.
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import csv
data = [{"name": "Davies", "faculty": "Eng", "dept": "EEE"},
{"name": "Smith", "faculty": "Eng", "dept": "Comp"}
]
with open("uni.csv", "w") as csv_file:
fieldnames = ["name", "faculty", "dept"]
writer = csv.DictWriter(csv_file, fieldnames=fieldnames, delimiter="|")
writer.writeheader()
writer.writerows(data)
And the output uni.csv file:
name|faculty|dept
Davies|Eng|EEE
Smith|Eng|Comp