Write a function that returns a sequence (index begins with 1) of all the even characters from a string. If the string is smaller than two characters or longer than 100 characters, the function should return "invalid string". 

For example:
`````
"abcdefghijklm" --> ["b", "d", "f", "h", "j", "l"]
"a"             --> "invalid string"
`````

Source: codewars | Difficulty: EASY
Tags: String algorithms

Fundamentals

Data structures

Starter code: def even_chars(st):
	

Solutions:
def even_chars(st):
	if len(st) < 2 or len(st) > 100:
		return 'invalid string'
	else:
		return [st[i] for i in range(1, len(st), 2)]


def even_chars(st):
	return list(st[1::2]) if 2 <= len(st) <= 100 else 'invalid string'


def even_chars(stg):
	return list(stg[1::2]) if 1 < len(stg) < 101 else 'invalid string'


def even_chars(st):
	return [x for (i, x) in enumerate(st) if i % 2 == 1] if 101 > len(st) > 1 else 'invalid string'


def even_chars(st):
	return len(st) < 101 and list(st[1::2]) or 'invalid string'