[課程討論] Day 12 - Beginner - Scope & Number Guessing Game

[Laurence]

Py基礎組，已於2021/4/25 PM 9:00，進行Day 12課程討論。
相關資訊，更新於此

[Laurence]

Questions.

1. Scope & Variable look-up: LEGB
2. return代表程式結束？return vs pass？
3. import, function, variable, and logic, which comes first？

[Laurence]

Python Scope & the LEGB Rule: Resolving Names in Your Code

Python Scope & the LEGB Rule: Resolving Names in Your Code – Real Python

[Laurence]

In Python, what is the difference between pass and return

In Python, what is the difference between pass and return

Is there a difference between continue and pass in a for loop in python?

Is there a difference between `continue` and `pass` in a for loop in python?

[Laurence]

Imports

PEP 8 -- Style Guide for Python Code

[Laurence]

Python 的 Import 陷阱
https://medium.com/pyladies-taiwan/python-的-import-陷阱-3538e74f57e3

[Laurence]

[Laurence]

在Python Taiwan上，看到的問題。我也是不懂為什麼，會是錯誤?
Google了一下，貼在這邊，當作紀錄。

a = 11

def test():
    print(a)
    a = 21

test()

UnboundLocalError: local variable 'a' referenced before assignment

[Day 14] 楚河漢界劃清楚！

[Day 14] 楚河漢界劃清楚！ - iT 邦幫忙::一起幫忙解決難題，拯救 IT 人的一天

[rabrus]

我的理解是:
在 test() 函數中，如果你想改變 global 變數( a=11)，就必須在 test()中先宣告為 global。

def test():
    global a
    print(a)
    a = 21

如果不想改變，那麼 a 在 test() 中就是 local 變數，a 就必須在 print(a) 之前宣告。

def test():
    a = 21
    print(a)

不先宣告的話，就會有那個錯誤訊息 local variable ‘a’ referenced before assignment。
有錯的話，煩請指正。