Focusing on common functions those that end up working with Natural Language Processing (NLP) will use. For now, we'll stick with the basic in-built functions, later on we'll deal with packages.
x = 'Weenis'
y = 'Raptah'
z = 'Deez'
x = x.lower()
y = y.lower()
z = z.lower()
print(x)
print(y)
print(z)
x = x.upper()
y = y.upper()
z = z.upper()
x = 'X' + x[1:]
y = 'X' + y[1:]
z = 'X' + z[1:]
x = 'Weenis'
y = 'Raptah'
z = 'Deez'
x = x.lower()
y = y.lower()
z = z.lower()
print(x)
print(y)
print(z)
x = x.upper()
y = y.upper()
z = z.upper()
print(x)
print(y)
print(z)
x = 'X' + x[1:]
y = 'X' + y[1:]
z = 'X' + z[1:]
print(x)
print(y)
print(z)