fix: condition for invalid prompt fixed

src/backend/langflow/api/base.py

@@ -28,10 +28,52 @@ class PromptValidationResponse(BaseModel):
     input_variables: list
 
 
+INVALID_CHARACTERS = {
+    " ",
+    ",",
+    ".",
+    ":",
+    ";",
+    "!",
+    "?",
+    "/",
+    "\\",
+    "(",
+    ")",
+    "[",
+    "]",
+    "{",
+    "}",
+}
+
+
 def validate_prompt(template: str):
     input_variables = extract_input_variables_from_prompt(template)
-    if invalid := [variable for variable in input_variables if " " in variable]:
-        raise ValueError(
-            f"Invalid input variables: {invalid}. Please remove spaces from input variables"
-        )
+
+    # Check if there are invalid characters in the input_variables
+    input_variables = check_input_variables(input_variables)
+
     return PromptValidationResponse(input_variables=input_variables)
+
+
+def check_input_variables(input_variables: list):
+    invalid_chars = []
+    fixed_variables = []
+    for variable in input_variables:
+        new_var = variable
+        for char in INVALID_CHARACTERS:
+            if char in variable:
+                invalid_chars.append(char)
+                new_var = new_var.replace(char, "")
+        fixed_variables.append(new_var)
+        if new_var != variable:
+            input_variables.remove(variable)
+            input_variables.append(new_var)
+    # If any of the input_variables is not in the fixed_variables, then it means that
+    # there are invalid characters in the input_variables
+    if any(var not in fixed_variables for var in input_variables):
+        raise ValueError(
+            f"Invalid input variables: {input_variables}. Please, use something like {fixed_variables} instead."
+        )
+
+    return input_variables