I have 2 lists let's say
a = [1,2,3]
b = [4,5,6]
I want to write them in two columns in CSV file so when I open the excel sheet I see something like this :
col1 col2
1 4
2 5
3 6
How can I do this?
I used zip(a,b) but the result is stored in one column:
col1
1 4
2 5
3 6
You need to use csv.Dictwriter() to be able to specify the field names.
import csv
with open('numbers.csv', 'w', newline='') as csvfile:
fieldnames = ['col1', 'col2']
writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
writer.writeheader()
for i, j in zip(a, b):
writer.writerow({'col1': i, 'col2': j})
Or instead of a regular for loop you could use writerows and a list comprehension:
writer.writerows([{'col1': i, 'col2': j} for i,j in zip(a,b)])
Using pandas is very easy. Just:
import pandas as pd
and then:
In [13]: df = pd.DataFrame({'col1':a, 'col2':b})
In [14]: df
Out[14]:
col1 col2
0 1 4
1 2 5
2 3 6
In [15]: df.to_csv('numbers.csv', index=False)
Basically you are building a dataframe with your lists and then save back to .csv. Hope that helps.
I found this solution, where you dont need an extra loop:
fieldnames = ["x_value", "y_value"]
def createcsv(fieldnames, file):
# csv for Data generation
with open(file, 'w') as csv_file:
csv_writer = csv.DictWriter(csv_file, fieldnames=fieldnames)
csv_writer.writeheader()
def writedata(x, y, fieldnames, file):
with open(file, 'a') as csv_file:
csv_writer = csv.DictWriter(csv_file, fieldnames=fieldnames)
info = {
"x_value": x,
"y_value": y
}
csv_writer.writerow(info)
Of course you could put those into one function, but this solution is created so that you can save your values during runtime, for example in a loop and dont have to create the fileheaders everytime again.
