为什么 IDLE shell 中出现这个 NameError？ [关闭]

Question

print('What is your name?')    # ask for their name
myName = input()  
print('It is good to meet you, ' + myName) 
print('The length of your name is:')
print(len(myName))

当我运行它时...

What is your name?
>>> bn
Traceback (most recent call last):
  File "<pyshell#6>", line 1, in <module>
    bn
NameError: name 'bn' is not defined

版本

>>> import sys; print(sys.version)
3.9.7 (tags/v3.9.7:1016ef3, Aug 30 2021, 20:19:38) [MSC v.1929 64 bit (AMD64)]

Answer 1

>>> bn

这意味着您在解释器 shell 上输入了bn，而不是之前的输入函数......

你可能想写这个而不是先打印

myName = input('What is your name? ')

---

您的错误也可能与 Python2 相关

例子

$ cat /tmp/app.py
print('What is your name?')    # ask for their name
myName = input()
print('It is good to meet you, ' + myName)
print('The length of your name is:')
print(len(myName))

$ python2 /tmp/app.py
What is your name?
bn
Traceback (most recent call last):
  File "/tmp/app.py", line 2, in <module>
    myName = input()
  File "<string>", line 1, in <module>
NameError: name 'bn' is not defined

$ python3 /tmp/app.py
What is your name?
bn
It is good to meet you, bn
The length of your name is:
2

如果你想使用Python2，你需要使用raw_input()，因为input()在输入的值上隐式调用eval()

Answer 2

您的环境一定有问题。您应该考虑卸载 Python 2。但是，请尝试运行此代码并告诉我们输出是什么：

import sys
print(sys.version[:5])
print('What is your name?')    # ask for their name
myName = input()  
print('It is good to meet you, ' + myName) 
print('The length of your name is:')
print(len(myName))

从 Py3.9 在 IDLE 中运行它，我得到以下输出：

Python 3.9.7 (tags/v3.9.7:1016ef3, Aug 30 2021, 20:19:38) [MSC v.1929
64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or
"license()" for more information.
>>> 
==== RESTART: C:\Users\Gary\Google Drive\Projects\StackOverflow\69651615.py ====
3.9.7
What is your name?
bn
It is good to meet you, bn
The length of your name is: 2
>>>