added stringfunctions.py

strings/stringfunctions.py

@@ -0,0 +1,76 @@
+''' These are the implementations of the basic string functions in python, 
+like isupper(), islower() and so on'''
+
+
+#function to check whether the string is in uppercase
+def is_upper(string):
+    if not string: 
+        return False
+    for character in string:
+        if ord(character) > 96 and ord(character) < 123: 
+            return False
+    return True
+
+#function to check whether the string is in lowercase
+def is_lower(string):
+    for character in string:
+        if ord(character) in range(65, 97):
+            return False
+    return True
+
+
+#function to check whether all characters in a string are alphabetical
+def is_alpha(string):
+    if(not string): 
+        return False
+    for character in string:
+        if ((ord(character) in range(65, 91)) or (ord(character) in range(97, 123))):
+            continue
+        else:
+            return False
+    return True
+
+#function to check for only alphanumeric characters
+def is_alnum(string):
+    if(not string): return False
+    for character in string:
+        if ((ord(character) in range(65, 91)) or (ord(character) in range(97, 123)) or (ord(character) in range(48, 58))):
+            continue
+        else:
+            return False
+    return True
+
+#function to check for digits only
+def is_decimal(string):
+    if(not string): return False
+    for character in string:
+        if(ord(character) not in range(48, 58)):
+            return False 
+    return True
+
+#function to check for spaces, tabs and newlines
+def is_space(string):
+    if(not string): return False
+    for character in string:
+        if(character !=' '):        #solve for newline pending
+            return False
+    return True
+
+#function to check whether first letter of each word is capital
+def is_title(s):
+    for substring in s.split():
+        if(ord(substring[0]) not in range(65, 91)):
+            return False
+        for character in range(1, len(substring)):
+            if(is_upper(substring[character])): 
+                return False
+    return True
+
+print(is_upper("HEY"))                          # True
+print(is_lower("there"))                        # True
+print(is_alpha("you"))                          # True
+print(is_alnum("are3"))                         # True
+print(is_decimal("400"))                        # True
+print(is_space("   "))                          # True
+print(is_title("Times Pretty"))                 # True
+