名称未定义 我已经定义了名称

Question

PFB the below code I am trying to calculate tax. why do I get the NameError: name 'tax' is not defined. I have defined tax below still it throws the error tax not defined.

    hw = float(input("Please enter total hours worked"))
    hp = float(input("Please enter the hourly rate"))

    # Pay and OT Calculations

    rp = hp * hw

    if hw == 40 or hw <40 :
        ot = 0
        tp = rp + ot

    elif hw > 40 and hw <50 :
        ot = (hw-40)*(hp*1.5)
        tp = rp + ot

    elif hw > 50 and hw < 60 :
        ot = (hw-40)*(hp*2)
        tp = rp + ot

    elif hw > 60 or hw == 60 :
        ot = (hw-40)*(hp*2.5)
        tp = rp + ot

    else :
        print ("Thanks")

    # tax Calculations

    if tp == 200 :
       tax = float((tp/100)*15)

    elif tp > 200 and tp < 300 :
         tax = ((tp-200)/100*20) + ((200/100)*15)

    elif tp >300 and tp < 400 :
         tax = ((tp-300)/100*25) + (((tp-200)-(tp-300))/100*20) + ((200/100)*15)

    elif tp >400 and tp == 400 :
         tax = ((tp-400)/100*30) + (((tp-200)-(tp-300)-(tp-400))/100*25) + (((tp-200)-(tp-300)/100)*20) + ((200/100)*15)

    else :
        print ("Thanks")

    # Printing Results

    print ("Your Salary has been credited")
    print ("Regular Pay = ", rp)
    print ("Overtime =", ot)
    print ("Gross Salary before tax deductions = ", tp)
    print ("Income Tax applicable =", tax)

Answer 1

you are using your variables across the entire function but are only defining them in the if/else cases. This adds a lot of room for error of missing a definition somewhere within a case as in

...
if tp == 200 :
       tax = float((tp/100)*15)

    elif tp > 200 and tp < 300 :
         tax = ((tp-200)/100*20) + ((200/100)*15)

    elif tp >300 and tp < 400 :
         tax = ((tp-300)/100*25) + (((tp-200)-(tp-300))/100*20) + ((200/100)*15)

    elif tp >400 and tp == 400 :
         tax = ((tp-400)/100*30) + (((tp-200)-(tp-300)-(tp-400))/100*25) + (((tp-200)-(tp-300)/100)*20) + ((200/100)*15)

    else :
        # NO tax defined here
        print ("Thanks")
...

You should define the function-scope variables on the top of your function as:

    hw = float(input("Please enter total hours worked"))
    hp = float(input("Please enter the hourly rate"))

    rp = 0
    ot = 0
    tp = 0
    tax = 0

    # Pay and OT Calculations
    ...
    # Printing Results

    print ("Your Salary has been credited")
    print ("Regular Pay = ", rp)
    print ("Overtime =", ot)
    print ("Gross Salary before tax deductions = ", tp)
    print ("Income Tax applicable =", tax)

By setting these default values you are sure to never miss the variable initialization in your code and you will not need to add extra logic to handle the tax variable in the edge cases where it should not be changed (the else case in your question.