A string is a sequence of characters and a list is a sequence of values, but a list of characters is not the same as a string. To convert from a string to a list of characters, you can use the list function:

list breaks a string into individual letters. If you want to break a string into words, you can use split method:

An optional argument called a delimiter specifies which characters to use as word boundaries. The following example uses ‘, ‘ ( a comma followed by a space) as the delimiter:

join is the inverse of split.  It takes a list of strings and concatenates the elements. join is a string method, so you have to invoke it on the delimiter and pass the list as a parameter:

In this case, delimiter is a space character, so join puts a space between words. to concatenate strings without spaces, you can use the empty string, ‘’ as delimiter.

from Thinking in Python