Python类型错误:无法解压缩不可迭代的布尔对象

Question

当我试图在列表中搜索时，我得到了TypeError: cannot unpack non-iterable bool object。当我返回布尔值和我正在搜索的项目的索引值时。

def name_ser(name):
found = False
for i in range(len(names)):
if names[i] == name:
found = True
return found, names.index(name)
else:
found = False
return found,None

def main_menu():
print('Welcome!nPlease Choose from the following options...')
print('1: Create an accountn2: Login ')
opt = int(input('Enter Your Choice: '))
if opt == 1:
name_search = input('Enter Name... ')
found, _ = name_ser(name_search)
if found == True:
print("Account Already excites!")
elif found == False & len(names) == 0:
acc_creation(name_search)
print('Account created!')

错误：

Traceback (most recent call last):
File "/Users/darkmbs/VS-Code/FirstPythonProject/accounts.py", line 100, in <module>
main_menu()
File "/Users/darkmbs/VS-Code/FirstPythonProject/accounts.py", line 77, in main_menu
found, _ = name_ser(name_search)
TypeError: cannot unpack non-iterable NoneType object

Answer 1

name_ser可以返回3个不同的对象。

def name_ser(name):
found = False
for i in range(len(names)):
if names[i] == name:
found = True
return found, names.index(name)     <== returns 2-tuple
else:                                   <== if name[0] doesn't match,
found = False                           executes immediately
return found                        <== returns boolean
<== if names is empty, returns None

您需要一个一致的返回类型。但实际上，这个函数根本不应该存在。它试图在names或False中返回name的索引。str.find几乎就是这样。

def main_menu():
print('Welcome!nPlease Choose from the following options...')
print('1: Create an accountn2: Login ')
opt = int(input('Enter Your Choice: '))
if opt == 1:
name_search = input('Enter Name... ')
if name_search in names:
print("Account Already exists!")
else:
acc_creation(name_search)
print('Account created!')

在添加帐户之前，我还删除了name_ser为空的复选框。如果只有一个人可以创建一个帐户，我觉得这会很奇怪。

Answer 2

正如前面的一些注释中所提到的，不能同时返回一个或两个值。我的建议是返回该名称的索引。或者，如果未找到，则返回值-1。

def name_ser(name):
# Check if element is in list
if name in names:
# Return index of element
return names.index(name)
else:
# Name was not found in the list
return -1
def main_menu():
print('Welcome!nPlease Choose from the following options...')
print('1: Create an accountn2: Login ')
opt = int(input('Enter Your Choice: '))
# Create account
if opt == 1:
name_search = input('Enter Name... ')
found = name_ser(name_search)
if found >= 0:
print("Account Already exists!")
elif found == -1 & len(names) == 0:
acc_creation(name_search)
print('Account created!')

# Login to Account
if opt == 2:
# Update to use index instead of boolean