[Answered ]-How to dynamically add an If Else statement in Python?

This problem looks interesting. Let me give my try,

I can see there are only three conditions that need to be performed. So let make a dictionary out of it:

con = {
"Equals": "==",
"Contain": "in",
"NotContain": "not in"
}

I can see you have the required values ready in hand here:

#Get all value from
ParameterGet = str(request.POST.get('Parameter', None))
ConditionGet = str(request.POST.get('Condition', None))
valuetomatch = str(request.POST["valuetomatch"])

Let’s take the for loop to iterate the table alert policies rows for iteration,

con = {
"Equals": "==",
"Contain": "in",
"NotContain": "not in"
}

for each_row in rows:
  ***your other logic goes here***
  ParameterGet = str(request.POST.get('Parameter', None))
  ConditionGet = str(request.POST.get('Condition', None))
  valuetomatch = str(request.POST["valuetomatch"])
  text = "body.decode('utf-8').rstrip()"
  current_condition = "(valuetomatch "+ con[ConditionGet] + " " + ParameterGet.lower() + ")"
  if eval(current_condition):
          server = smtplib.SMTP('smtp.gmail.com', 587)
          server.starttls()
          server.login(EMAIL_ACCOUNT, PASSWORD)
          msg = "subject not contain!"
          server.sendmail(EMAIL_ACCOUNT, "xxx@gmail.com", msg)
          server.quit()
  else:
          print("no email");

OUTPUT:

>>> con = {
"Equals": "==",
"Contain": "in",
"NotContain": "not in"
}
>>> valuetomatch = "hi"
>>> ConditionGet = "Contain"
>>> ParameterGet = "Subject"
>>> subject = "hi"
>>> current_condition = "(valuetomatch "+ con[ConditionGet] + " " + ParameterGet.lower() + ")"
>>> current_condition
'(valuetomatch in subject)'
>>> eval(current_condition)
True

Check eval for reference.

You could try something like this in server side:

# What you get from frontend
arr=[["Subject","Equals","test"],["Text","Contain","Testing 1 2 3"],["Text","Contain","rhrhj"]]
email_message = email.message_from_string(raw_email_string)
subject = str(email.header.make_header(email.header.decode_header(email_message['Subject'])))

# Dict with mapping between patterns and objects
to_compare = {
    'Subject': subject,
    'Text': email_message,
}

# Returns right object between email_message or subject
def get_compare(target, to_compare):
    try:
        return to_compare[target]
    except:
        raise Exception(f"{target} not found in comparable elements.")
    
# Loop over arr, perform checks and do actions
for alert in arr:
    if arr[1] == 'Equals':
        if get_compare(arr[0]) == arr[3]:
            # Do something
        
    elif arr[1] == 'Contain':
        if arr[3] in get_compare(arr[0]):
            # Do something
        
    elif arr[1] == 'NotContain':
        if arr[3] not in get_compare(arr[0]):
            # Do something
        
    else:
        raise Exception(f"{arr[1]} does not belong to recognize operators.")