1. 错误信息
Traceback (most recent call last):
File "D:\Anaconda\lib\site-packages\IPython\core\interactiveshell.py", line 3418, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-4-f12639514596>", line 1, in <module>
meanU, np_subdf = Trans3D(np_subdf_ori)
ValueError: too many values to unpack (expected 2)
2. 原因分析
2.1 Cause 1: List Unpacking
appliances = ['Fridge', 'Microwave', 'Toaster']
appliance_1, appliance_2 = appliances
OUT:
ValueError Traceback (most recent call last)
<ipython-input-4-2c62c443595d> in <module>
1 appliances = ['Fridge', 'Microwave', 'Toaster']
----> 2 appliance_1, appliance_2 = appliances
ValueError: too many values to unpack (expected 2)
Solution
appliances = ['Fridge', 'Microwave', 'Toaster']
appliance_1, appliance_2, appliance_3 = appliances
2.2 Unpacking Function Returns
def compute(x, y):
sum = x + y
product = x * y
quotient = x / y
return sum, product, quotient
result_1, result_2 = compute(12, 5)
OUT:
ValueError Traceback (most recent call last)
<ipython-input-5-9e571b686b4f> in <module>
6 return sum, product, quotient
7
----> 8 result_1, result_2 = compute(12, 5)
ValueError: too many values to unpack (expected 2)
Solution 1
First we’ll define the function once more:
def compute(x, y):
sum = x + y
product = x * y
quotient = x / y
return sum, product, quotient
result_1, result_2, result_3 = compute(12, 5)
Solution 2
Using a underscore to throw away a return value:
result_1, result_2, _ = compute(12, 5)
