I have a list of lists as below. a = [[1,2,3], [2,3,4], [3,4,5]]
I also have a separate list of names names = ['Ann', 'john', 'smith']
Now I want to write this into a csv file as below
1st row: Ann,1,2,3
2nd row: john,2,3,4
3rd row: smith,3,4,5
I am currently using;
with open(output_file, 'w') as f:
writer = csv.writer(f)
writer.writerows(a)
However, it does not do the job I want as it always starts from the first column, instead of the second column. Please help me.
The key point to understand here is that you want to process your list in parallel. This can easily be accomplished by using the built-in function zip. It takes an list of iterables, and yields the n-th element of each iterable as a tuple. You can then format your lines by using str.format:
names = ['Ann', 'john', 'smith']
sublists = [[1,2,3], [2,3,4], [3,4,5]]
with open(output_file, 'w') as file:
for name, sublist in zip(names, sublists):
row = '{},{},{},{}'.format(name, *sublist)
file.write(row)
Note if your lists are different sizes, you may want to look into using itertools.zip_longest.
with open(output_file, 'w') as f:
f.write('\n'.join([elem[0]+','+str(elem[1]).strip('[').strip(']') for elem in zip(names,a)]))
Try this.
with open("output_file", 'w') as f:
f.write("\n".join([','.join(map(str, [name] + extra)) for name, extra in zip(name, extras)])
