Convert a list of characters into a string
This works in many popular languages like JavaScript and Ruby, why not in Python?
>>> ['a', 'b', 'c'].join('')Traceback (most recent call last): File "<stdin>", line 1, in <module>AttributeError: 'list' object has no attribute 'join'
Strange enough, in Python the join
method is on the str
class:
# this is the Python way"".join(['a','b','c','d'])
Why join
is not a method in the list
object like in JavaScript or other popular script languages? It is one example of how the Python community thinks. Since join is returning a string, it should be placed in the string class, not on the list class, so the str.join(list)
method means: join the list into a new string using str
as a separator (in this case str
is an empty string).
Somehow I got to love this way of thinking after a while. I can complain about a lot of things in Python design, but not about its coherence.
If your Python interpreter is old (1.5.2, for example, which is common on some older Linux distributions), you may not have join()
available as a method on any old string object, and you will instead need to use the string module. Example:
a = ['a', 'b', 'c', 'd']try: b = ''.join(a)except AttributeError: import string b = string.join(a, '')
The string b
will be 'abcd'
.