最近学 Python ，关于作用域的问题有点不明白

[dwlovelife]

def foo():
    c = "hello"
    x = 0
    def bar():
        b = True
        print(a)
        print(b)
        print(c)
        x = a
    bar()
    print(x)


if __name__ == "__main__":
    a = 100
    foo()

结果就是： 100 True hello 0

问题 1： 为什么在 bar 函数内能访问 a 呢 问题 2： 能访问按道理能赋值啊，x 咋还是 0

[NanFengXiangWan]

因为变量 a 是全局作用域

[flyhelan]

<section id="nice" data-tool="mdnice 编辑器" data-website="https://www.mdnice.com" style="font-size: 16px; color: black; padding: 0 10px; line-height: 1.6; word-spacing: 0px; letter-spacing: 0px; word-break: break-word; word-wrap: break-word; text-align: left; font-family: Optima-Regular, Optima, PingFangSC-light, PingFangTC-light, 'PingFang SC', Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;"><pre class="custom" data-tool="mdnice 编辑器" style="margin-top: 10px; margin-bottom: 10px; border-radius: 5px; box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;"><span style="display: block; background: url( https://files.mdnice.com/user/3441/876cad08-0422-409d-bb5a-08afec5da8ee.svg); height: 30px; width: 100%; background-size: 40px; background-repeat: no-repeat; background-color: #282c34; margin-bottom: -7px; border-radius: 5px; background-position: 10px 10px;"></span><code class="hljs" style="overflow-x: auto; padding: 16px; color: #abb2bf; display: -webkit-box; font-family: Operator Mono, Consolas, Monaco, Menlo, monospace; font-size: 12px; -webkit-overflow-scrolling: touch; padding-top: 15px; background: #282c34; border-radius: 5px;"><span class="hljs-function" style="line-height: 26px;"><span class="hljs-keyword" style="color: #c678dd; line-height: 26px;">def</span>&nbsp;<span class="hljs-title" style="color: #61aeee; line-height: 26px;">foo</span><span class="hljs-params" style="line-height: 26px;">()</span>:</span><br>&nbsp;&nbsp;&nbsp;&nbsp;c&nbsp;=&nbsp;<span class="hljs-string" style="color: #98c379; line-height: 26px;">"hello"</span><br>&nbsp;&nbsp;&nbsp;&nbsp;x&nbsp;=&nbsp;<span class="hljs-number" style="color: #d19a66; line-height: 26px;">0</span><br>&nbsp;&nbsp;&nbsp;&nbsp;<span class="hljs-function" style="line-height: 26px;"><span class="hljs-keyword" style="color: #c678dd; line-height: 26px;">def</span>&nbsp;<span class="hljs-title" style="color: #61aeee; line-height: 26px;">bar</span><span class="hljs-params" style="line-height: 26px;">()</span>:</span><br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;b&nbsp;=&nbsp;<span class="hljs-literal" style="color: #56b6c2; line-height: 26px;">True</span><br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(a)<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(b)<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(c)<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x&nbsp;=&nbsp;a<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print(x)&nbsp;<span class="hljs-comment" style="color: #5c6370; font-style: italic; line-height: 26px;">#&nbsp;新增这条</span><br>&nbsp;&nbsp;&nbsp;&nbsp;bar()<br>&nbsp;&nbsp;&nbsp;&nbsp;print(x)<br><br><br><span class="hljs-keyword" style="color: #c678dd; line-height: 26px;">if</span>&nbsp;__name__&nbsp;==&nbsp;<span class="hljs-string" style="color: #98c379; line-height: 26px;">"__main__"</span>:<br>&nbsp;&nbsp;&nbsp;&nbsp;a&nbsp;=&nbsp;<span class="hljs-number" style="color: #d19a66; line-height: 26px;">100</span><br>&nbsp;&nbsp;&nbsp;&nbsp;foo()<br></code></pre>
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