[Python] 알파벳/숫자인지 확인(isalpha, isdigit, isalnum)

📍isalpha : 알파벳인지 확인

a = '1q2w3e4r'
b = '1234'
c = "qwer"
 
print(a.isdigit()) #False -> 숫자와 섞임
print(b.isdigit()) #True
print(c.isdigit()) #False

📍isdigit : 숫자인지 확인

a = '1q2w3e4r'
b = '1234'
c = "qwer"
 
print(a.isalpha()) #False -> 알파벳과 섞임
print(b.isalpha()) #False
print(c.isalpha()) #True

📍isalnum : 알파벳 or 숫자인지 확인

a = '1q2w3e4r'
b = '1234'
c = "qwer"
d = "****"
e = '1q2/w3e4r'

print(a.isalnum()) #True
print(b.isalnum()) #True
print(c.isalnum()) #True
print(d.isalnum()) #False -> 특수문자는 false
print(e.isalnum()) #False -> 특수문자와 섞임