How can I check if a string contains ANY letters from the alphabet?

Question

What is best pure Python implementation to check if a string contains ANY letters from the alphabet?

string_1 = \"(555).555-5555\"
string_2 = \"(555) 555 - 5         


        

Answer 1

I liked the answer provided by @jean-françois-fabre, but it is incomplete.
His approach will work, but only if the text contains purely lower- or uppercase letters:

>>> text = "(555).555-5555 extA. 5555"
>>> text.islower()
False
>>> text.isupper()
False

The better approach is to first upper- or lowercase your string and then check.

>>> string1 = "(555).555-5555 extA. 5555"
>>> string2 = '555 (234) - 123.32   21'

>>> string1.upper().isupper()
True
>>> string2.upper().isupper()
False