Python Help needed

[StevenFama]

I have a script that populates/updates a field based upon its content. If none of the conditions are true, I need it not to update / return <Null>. 

def Reclass(StoryHeight_Copy): 
if (StoryHeight_Copy == "1A"): 
return "1.25" 
elif (StoryHeight_Copy == "1H"): 
return "1.50" 
elif (StoryHeight_Copy == "1T"): 
return "1.75" 
elif (StoryHeight_Copy == "2A"): 
return "2.25"
elif (StoryHeight_Copy == "2H"): 
return "2.50" 
elif (StoryHeight_Copy == "2T"): 
return "2.75" 
elif (StoryHeight_Copy == "3A"): 
return "3.25"
elif (StoryHeight_Copy == "3H"): 
return "3.50" 
elif (StoryHeight_Copy == "3T"): 
return "3.75"

[DanPatterson_Retired]

PEP 8 ... would help as well and going forward in Python 3.5+, PEP484... only a few covered here to improve readability.

Code Formatting... the basics ++ as well as others is useful to provide clean code with consistent indentation for the novice pythonista

def Reclass(StoryHeight_Copy):
    d = {"1A": "1.25", "1H": "1.5", "1T": "1.75"}
    if StoryHeight_Copy in d:
        return d[StoryHeight_Copy]
    return None‍‍‍‍‍

[XanderBakker]

I the examples shared by carl anderson  and Dan Patterson there should be an else statement that returns the original value in case it is not in the dictionary as curtvprice  showed earlier.