Python | Comprobar si una string dada es una string binaria o no

String dada str. La tarea es verificar si es una string binaria o no. 

Ejemplos:  

Input: str = "01010101010"
Output: Yes

Input: str = "geeks101"
Output: No

Enfoque 1 : Uso de Set  

1. Inserta la string dada en un conjunto
2. Compruebe si los caracteres establecidos constan de 1 y/o 0 solamente.

Ejemplo:

# Python program to check
# if a string is binary or not
 
# function for checking the
# string is accepted or not
 
 
def check(string):
 
    # set function convert string
    # into set of characters .
    p = set(string)
 
    # declare set of '0', '1' .
    s = {'0', '1'}
 
    # check set p is same as set s
    # or set p contains only '0'
    # or set p contains only '1'
    # or not, if any one condition
    # is true then string is accepted
    # otherwise not .
    if s == p or p == {'0'} or p == {'1'}:
        print("Yes")
    else:
        print("No")
 
 
# driver code
if __name__ == "__main__":
 
    string = "101010000111"
 
    # function calling
    check(string)

Yes

Enfoque 2: iteración simple 

1. Iterar para cada carácter y verificar si el carácter es 0 o 1.
2. Si no es así, establezca un contador y rompa.
3. Después de la iteración, compruebe si el contador está configurado o no.

# Python program to check
# if a string is binary or not
 
# function for checking the
# string is accepted or not
 
 
def check2(string):
 
    # initialize the variable t
    # with '01' string
    t = '01'
 
    # initialize the variable count
    # with 0 value
    count = 0
 
    # looping through each character
    # of the string .
    for char in string:
 
        # check the character is present in
        # string t or not.
        # if this condition is true
        # assign 1 to the count variable
        # and break out of the for loop
        # otherwise pass
        if char not in t:
            count = 1
            break
        else:
            pass
 
    # after coming out of the loop
    # check value of count is non-zero or not
    # if the value is non-zero the en condition is true
    # and string is not accepted
    # otherwise string is accepted
    if count:
        print("No")
    else:
        print("Yes")
 
 
# driver code
if __name__ == "__main__":
 
    string = "001021010001010"
 
    # function calling
    check2(string)

No

Enfoque 3 : expresiones regulares

1. Compile una expresión regular usando compile() para «el carácter no es 0 o 1».
2. Use re.findall() para obtener las strings que satisfacen la expresión regular anterior.
3. Imprimir salida basada en el resultado.

#import library
import re
 
sampleInput = "1001010"
 
# regular expression to find the strings
# which have characters other than 0 and 1
c = re.compile('[^01]')
 
# use findall() to get the list of strings
# that have characters other than 0 and 1.
if(len(c.findall(sampleInput))):
    print("No") # if length of list > 0 then it is not binary
else:
    print("Yes") # if length of list = 0 then it is binary

Yes

Enfoque 4: Uso del manejo de excepciones e int

Python tiene un método incorporado para convertir una string de una base específica a un entero decimal, usando int(string, base) . Si la string pasada como argumento no tiene la base especificada, se genera un ValueError.

# Python program to check
# if a string is binary or not
 
# function for checking the
# string is accepted or not
 
 
def check(string):
    try:
        # this will raise value error if
        # string is not of base 2
        int(string, 2)
    except ValueError:
        return "No"
    return "Yes"
 
 
# driver code
if __name__ == "__main__":
 
    string1 = "101011000111"
    string2 = "201000001"
 
    # function calling
    print(check(string1))
    print(check(string2))
 
 
# this code is contributed by phasing17

Yes
No

Complejidad de Tiempo: O(1), Espacio Auxiliar: O(1)

Enfoque 5: Uso de la función de conteo()

string = "01010101010"
if(string.count('0')+string.count('1')==len(string)):
    print("Yes")
else:
    print("No")

Yes