Good morning everyone.
I have a csv file with 3 columns: product, quantity and price.
I want to create 3 list, one for each column.
I try with the following code, but this create a list for each row instead of a list for each column. Any idea, please??
Thanks in advance :)
import csv
with open ("./02_CSV_data.csv","r") as myCSV:
contenido=csv.reader(myCSV)
for i in contenido:
print(i)
Append each element of the list to the appropriate list.
import csv
products = []
quantities = []
prices = []
with open ("./02_CSV_data.csv","r") as myCSV:
contenido=csv.reader(myCSV)
for i in contenido:
products.append(i[0])
quantities.append(i[1])
prices.append(i[2])
I know you are trying to do this with csv but Pandas can do this easily :
Install Pandas using pip:
pip install pandas
Code to convert csv columns to list:
import pandas as pd
df = pd.read_csv(r'path/of/csv/file.csv')
list1 = df['col_name_1'].to_list()
list2 = df['col_name_2'].to_list()
list3 = df['col_name_3'].to_list()
You can transpose the read in rows - this is less efficient then Barmars solution though - it creates the big list of data and then creates 3 smaller lists from it instead of only creating the smaller lists:
Create data:
with open ("./02_CSV_data.csv","w") as f:
f.write("""
1,1a,1b
2,2a,2b
3,3a,3b
""")
Read data as rows:
import csv
data = []
with open ("./02_CSV_data.csv","r") as myCSV:
contenido = csv.reader(myCSV)
for i in contenido:
if i: # avoid empty rows
data.append(i)
Extract colums using zip():
products, quantities, prices = map(list, zip(*data))
print(products)
print(quantities)
print(prices)
Output:
['1', '2', '3']
['1a', '2a', '3a']
['1b', '2b', '3b']
