---
# System prepended metadata

title: 第六週3/21

---

# 第六週3/21

### 追蹤程式碼(trace)
例子：
```
A = [1,2,3]
y = 0
for x in A
    y = y + x
    
print(y)
```

|     | 1   | 2   | 3   |
| --- | --- | --- | --- |
| x   | 1   | 2   | 3   |
| y   | 1   | 3   | 6   |