Writing to CSV without tokenizing words into letters

Question

So, I want to take the keys from the dictionary "data" [see code below] and write to a csv file a row of headers, so I'll have two columns, "name" and "language." Then I want to have four rows, the first being "Dave,Python", the second "Dennis,C" and so on. Should look like:

name,language
Dave,Python
Dennis,C
Peter,Java
Jess,Python

Code:

data = {
    'name': ['Dave', 'Dennis', 'Peter', 'Jess'],
    'language': ['Python', 'C', 'Java', 'Python']
}

with open("dump.csv", mode="w", newline="") as f:
    writer = csv.writer(f, delimiter=",")
    writer.writerow(data.keys())
    for n, l in zip(data["name"], data["language"]):
        writer.writerow(f'{n}{l}')

Here's what I'm actually getting:

name,language
D,a,v,e,P,y,t,h,o,n
D,e,n,n,i,s,C
P,e,t,e,r,J,a,v,a
J,e,s,s,P,y,t,h,o,n

I'm pretty sure this is happening because strings are indexed in Python and my for n, l [etc.] line is somehow iterating over each index of the strings, but I don't know why it's happening or what to do to fix it.

Answer 1

Under the hood, strings are just arrays of characters. Meanwhile, writerow() expects an array of values to be turned into a row of fields. Instead, you're passing it a string you've combined together which results in each character being interpreted as a field.

You could either recombine n and l back into an array

writer.writerow([n, l])

Or simply don't bother destructuring the enumerated value from the zip() operation.

for row in zip(data["name"], data["language"]):
    writer.writerow(row)

Answer 2

.writerow() takes an iterable as an argument and writes all the parts as separate values to the csv.

You're giving it a string ( f'{n}{l}' ) and that's an iterable of characters, which explains the output you get.

You should do this instead:

        writer.writerow([n, l])

That gives it a list of strings, writing each string to its own position, without breaking it up.

Answer 3

[Overkill] If you do not mind to add a (unnecessary) package, Pandas can ease the task.

import pandas as pd

data = {
    'name': ['Dave', 'Dennis', 'Peter', 'Jess'],
    'language': ['Python', 'C', 'Java', 'Python']
}

df = pd.DataFrame(data)
df.to_csv("dump.csv", index=False)