write float list to csv file

Question

I have a list of float numbers, its format is:

float_list = [1.13, 0.25, 3.28, ....]

I used following code to write it to a .csv file:

float_str = ""

for result in result_list:
    float_str = float_str + str(result.get_value()) + ","

with open(output_path, "wb") as file:
    writer = csv.writer(file)
    writer.writerow(float_str)

file.close()

where result.get_value() is:

def get_value():
    return float(value)

I expect to see that in each cell, there is a value. However, what I've got looks like:

1   .   1   3   ,    0   .   2    5   ,  3   .   2   8   ,

It seems that each of the digits occupies a cell.

So, may I know how can I solve this issue and get what I expected?

Answer 1

The writer.writerow() takes a sequence (a list or tuple), but you are passing in a string instead. By passing in a string, writer.writerow() still treats it as as sequence, and each individual character becomes a column value:

1,.,1,3,,,0,.,2,5,,,3,.,2,8

Moreover, the method converts column to strings for you, don't do this yourself.

Instead build a list of your float values and pass that in:

row = []
for result in result_list:
    row.append(result.get_value())

with open(output_path, "wb") as file:
    writer = csv.writer(file)
    writer.writerow(row)

or even:

with open(output_path, "wb") as file:
    writer = csv.writer(file)
    writer.writerow([r.get_value() for r in result_list])

The delimiter defaults to ,.