', '.join(strings) can be used to concatenate all strings in a list.
Now I have a list storing objects, and I'd like to join their names together. e.g.:
>>> a=[{'name': 'John', 'age': '21'},{'name': 'Mark', 'age': '25'}]
>>> a[0]['name'] + ', ' + a[1]['name']
'John, Mark'
Is there a simple way like join() above to do this?
You have list of dictionaries not list of objects. We can join them together like this
print ", ".join(d["name"] for d in a)
d["name"] for d in a is called a generator expression, str.join will get the values from the generator expression one by one and join all of them with , in the middle.
But, if the list of dictionaries is too big then we can create a list of strings ourselves and pass it to the str.join like this
print ", ".join([d["name"] for d in a])
Here, [d["name"] for d in a] is called list comprehension, which iterates through a and creates a new list with all the names and we pass that list to be joined with ,.
I just noticed the discussion in the comments section. Please check this answer to know, why List Comprehension is better than GenExp in string joining.
', '.join([x['name'] for x in a])I doubt there's anything simpler.strings.join(', ')is from JS, right?','.join(x['name'] for x in a).join.