a = ",".join('abcd')
print(a)

b = ",".join(['a','b','c','d'])
print(b)

c = 'hi'
d = c.upper()
print(d)

e = 'HI'
f = e.lower()
print(f)

g = ' hi '
h = g.lstrip(); print(h)

i = ' hi '
j = i.rstrip(); print(j)

k = ' hi '
l = k.strip(); print(l)

m = "Life is too short"
n = m.replace("Life", "Your leg"); print(n)