Python program to validate string has few selected type of characters or not

Suppose we have a string s. We have to check whether the string contains the following or not.

• Numbers

• Lowercase letters

• Uppercase letters

Note − There may be some other symbols, but these three must be there

So, if the input is like s = "p25KDs", then the output will be True

To solve this, we will follow these steps −

• arr := an array of size 3 and fill with False
• for each character c in s, do
  • if c is alphanumeric, then
    • arr[0] := True
  • if c is in lowercase, then
    • arr[1] := True
  • if c is in uppercase, then
    • arr[2] := True
• return true when all items of arr are true

Example

Let us see the following implementation to get better understanding

def solve(s):
   arr = [False]*3
   for c in s:
      if c.isalnum():
         arr[0] = True
      if c.islower():
         arr[1] = True
      if c.isupper():
          arr[2] = True

   return all(arr)

s = "p25KDs"
print(solve(s))

Input

"p25KDs"

Output

True