Comprehension list

Question

I would like to get example contains Comprehension list with join() function for learning

Answer 1

# List comprehension is a shorthand way to initialize a list, as you can do through more explicit looping:

myList = [ chr(i+97) for i in range(5) ]

# is equivalent to:

myList = [ ]
for i in range(5):
myList.append(chr(i+97))

# obviously, expression used in list comprehension could be more complex ^^

# on the other hand, the string join() method (in other languages join() is often a method of array/list objects) concatenate all items of a list to a string with a separator (or not), but in Python, you must be aware that you cannot implicitly append other type than string to string:

# previous myList is now equal to: [ 'a', 'b', 'c', 'd', 'e' ]
myString = ':'.join(myList) # 'a:b:c:d:e'

myIntList = [ 1, 2, 3 ]
# myString = ':'.join(myIntList) # error
myString = ':'.join([ str(value) for value in myIntList ]) # '1:2:3'