Python function NameError [duplicate]

问题

This question already has an answer here:

Why am I getting a NameError when I try to call my function? (1 answer)

Closed 8 months ago.

I am using python 3.4.1. I keep getting this error,

 (NameError: name 'calcHullSpeed' is not defined)

What am I doing wrong?

import math

LWL = float(input("Enter the length of the boat: "))
maxHullSpeed = calcHullSpeed(LWL)
print("The hull speed is: " + str(round(maxHullSpeed,2)))

def calcHullSpeed(LWL):
    maxHS = 1.34*math.sqrt(LWL)
    return maxHS

回答1:

Put your function first:

def calcHullSpeed(LWL):
    maxHS = 1.34*math.sqrt(LWL)
    return maxHS

LWL = float(input("Enter the length of the boat: "))
maxHullSpeed = calcHullSpeed(LWL)
print("The hull speed is: " + str(round(maxHullSpeed,2)))

Functions have to be defined before you call them.

来源：https://stackoverflow.com/questions/26152661/python-function-nameerror