Mixed function

[Truman]

My final work is to add elements that I used so far in different programs. I wrote this code:

def str_analysis(argstr):
    
    if argstr.isdigit() > 100:
        if argstr.isdigit() > 1000:
            print("We have a big number!")
        else:
            print("we have a moderately big number")
    elif argstr.isdigit() < 100:
        print("We have a small number!")
    elif argstr.isalpha():
        print("We have all alphabetic!")
    else:
        print("We have multiple character type")
str_analysis(input("Add string: "))

What ever input I give it prints "We have a small number!". Don't understand why.