I have a simple function to read the csv file and extracts the first coloum from it:
import csv def pass_username(): with open('test.csv', 'r') as csvfile: spamreader = csv.reader(csvfile, delimiter=',') for row in spamreader: return row
When I call this function as:
a = pass_username() print a
This only prints the first element. However, when I replace
return word with
print row and call the function as
pass_username() it prints all the elements. I want to assign that function to a variable thus I want to use return. How to fix it?
Content of test.csv:
"firstname.lastname@example.org","rockon" "email@example.com","hey" "firstname.lastname@example.org","ok" "email@example.com","password"
As the other people who answered said, you can accumulate the results into a list and return that. Another way though, would be to replace
yield which causes your function to return an iterable type object that produces the items you yield when you decide to iterate over it later (possibly with a for loop).
Here is how you would use it with your code:
import csv def pass_username(): with open('test.csv', 'r') as csvfile: spamreader = csv.reader(csvfile, delimiter=',') for row in spamreader: yield row username_generator = pass_username() # iterate through the usernames with a for loop for name in username_generator: print name # call the list constructor which causes it to produce all of the names print list(pass_username())
Keep in mind that the usernames are produced as they are needed, so you can, for example, do
username_generator.next() which will produce the next username without having to produce all of them.
When you call
return, it autimtically exits out of the function, so it doesn’t process anything after it reaches the
You might want to
append the result to a list, then
return the list.
In your case, you might even want to use a
list comprehension, so instead of the for loop, use this:
return [row for row in spamreader]
You can only return once from a function. When it returns, it’s over. The first time your function returns, it ends, so it only returns one value.
If you want to return all the values, accumulate them into a list and return the list.