more efficient

pass.py

@@ -1,45 +1,15 @@
-#generate weak, medium, strong password 
+import string
 import random
 
-DIGITS = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
-
-LOCASE_CHARACTERS = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u',
-                     'v', 'w', 'x', 'y', 'z']
-
-UPCASE_CHARACTERS = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'M', 'N', 'O', 'p', 'Q', 'R', 'S', 'T', 'U',
-                     'V', 'W', 'X', 'Y', 'Z']
-
-SYMBOLS = ['@', '#', '$', '%', '=', ':', '?', '.', '/', '|', '~', '>', '*', '(', ')']
-
-def password_generator(p,l,s) :
-	random.shuffle(s)    
-	while len(p) < l :
-		p += random.choice(s)
-	a = []
-	for i in p :
-		a.append(i)
-	random.shuffle(a) 
-	p = ""
-	for i in a :
-		p += i
-	return p	
-
-print("Select Password Strength :\n1. Weak\n2. Medium\n3. Strong")
-ch = int(input("Enter Choice : "))
-if ch == 1 :
-	pass_length = 8
-	password = random.choice(LOCASE_CHARACTERS)*2 + random.choice(UPCASE_CHARACTERS)*2 #contain atleast one character from each set
-	combined = list((LOCASE_CHARACTERS+UPCASE_CHARACTERS))
-	key = password_generator(password,pass_length,combined)
-elif ch == 2 :
-	pass_length = random.randint(9,12)
-	password = random.choice(DIGITS) + random.choice(LOCASE_CHARACTERS) + random.choice(UPCASE_CHARACTERS) #contain atleast one character from each set
-	combined = list((DIGITS+LOCASE_CHARACTERS+UPCASE_CHARACTERS))
-	key = password_generator(password,pass_length,combined)
-else :
-	pass_length = 13
-	password = random.choice(DIGITS) + random.choice(LOCASE_CHARACTERS) + random.choice(UPCASE_CHARACTERS) + random.choice(SYMBOLS) #contain atleast one character from each set
-	combined = list((DIGITS+LOCASE_CHARACTERS+UPCASE_CHARACTERS+SYMBOLS))
-	key = password_generator(password,pass_length,combined)
-
-print(key)
+if __name__ == "__main__":
+    s1=string.ascii_lowercase
+    s2=string.ascii_uppercase
+    s3=string.digits
+    s4=string.punctuation
+    plen=int(input("Enter Password Length\n"))
+    s=[]
+    s.extend(list(s1))
+    s.extend(list(s2))
+    s.extend(list(s3))
+    random.shuffle(s)
+    print("".join(s[0:plen]))