figure:last-child { margin-bottom: 0.5rem; }
#write ol, #write ul { position: relative; }
img { max-width: 100%; vertical-align: middle; }
button, input, select, textarea { color: inherit; font: inherit; }
input[type="checkbox"], input[type="radio"] { line-height: normal; padding: 0px; }
*, ::after, ::before { box-sizing: border-box; }
#write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write p, #write pre { width: inherit; }
#write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write p { position: relative; }
p { line-height: inherit; }
h1, h2, h3, h4, h5, h6 { break-after: avoid-page; break-inside: avoid; orphans: 2; }
p { orphans: 4; }
h1 { font-size: 2rem; }
h2 { font-size: 1.8rem; }
h3 { font-size: 1.6rem; }
h4 { font-size: 1.4rem; }
h5 { font-size: 1.2rem; }
h6 { font-size: 1rem; }
.md-math-block, .md-rawblock, h1, h2, h3, h4, h5, h6, p { margin-top: 1rem; margin-bottom: 1rem; }
.hidden { display: none; }
.md-blockmeta { color: rgb(204, 204, 204); font-weight: 700; font-style: italic; }
a { cursor: pointer; }
sup.md-footnote { padding: 2px 4px; background-color: rgba(238, 238, 238, 0.7); color: rgb(85, 85, 85); border-radius: 4px; cursor: pointer; }
sup.md-footnote a, sup.md-footnote a:hover { color: inherit; text-transform: inherit; text-decoration: inherit; }
#write input[type="checkbox"] { cursor: pointer; width: inherit; height: inherit; }
figure { overflow-x: auto; margin: 1.2em 0px; max-width: calc(100% + 16px); padding: 0px; }
figure > table { margin: 0px !important; }
tr { break-inside: avoid; break-after: auto; }
thead { display: table-header-group; }
table { border-collapse: collapse; border-spacing: 0px; width: 100%; overflow: auto; break-inside: auto; text-align: left; }
table.md-table td { min-width: 32px; }
.CodeMirror-gutters { border-right: 0px; background-color: inherit; }
.CodeMirror-linenumber { user-select: none; }
.CodeMirror { text-align: left; }
.CodeMirror-placeholder { opacity: 0.3; }
.CodeMirror pre { padding: 0px 4px; }
.CodeMirror-lines { padding: 0px; }
div.hr:focus { cursor: none; }
#write pre { white-space: pre-wrap; }
#write.fences-no-line-wrapping pre { white-space: pre; }
#write pre.ty-contain-cm { white-space: normal; }
.CodeMirror-gutters { margin-right: 4px; }
.md-fences { font-size: 0.9rem; display: block; break-inside: avoid; text-align: left; overflow: visible; white-space: pre; background: inherit; position: relative !important; }
.md-diagram-panel { width: 100%; margin-top: 10px; text-align: center; padding-top: 0px; padding-bottom: 8px; overflow-x: auto; }
#write .md-fences.mock-cm { white-space: pre-wrap; }
.md-fences.md-fences-with-lineno { padding-left: 0px; }
#write.fences-no-line-wrapping .md-fences.mock-cm { white-space: pre; overflow-x: auto; }
.md-fences.mock-cm.md-fences-with-lineno { padding-left: 8px; }
.CodeMirror-line, twitterwidget { break-inside: avoid; }
.footnotes { opacity: 0.8; font-size: 0.9rem; margin-top: 1em; margin-bottom: 1em; }
.footnotes + .footnotes { margin-top: 0px; }
.md-reset { margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: top; background: 0px 0px; text-decoration: none; text-shadow: none; float: none; position: static; width: auto; height: auto; white-space: nowrap; cursor: inherit; -webkit-tap-highlight-color: transparent; line-height: normal; font-weight: 400; text-align: left; box-sizing: content-box; direction: ltr; }
li div { padding-top: 0px; }
blockquote { margin: 1rem 0px; }
li .mathjax-block, li p { margin: 0.5rem 0px; }
li { margin: 0px; position: relative; }
blockquote > :last-child { margin-bottom: 0px; }
blockquote > :first-child, li > :first-child { margin-top: 0px; }
.footnotes-area { color: rgb(136, 136, 136); margin-top: 0.714rem; padding-bottom: 0.143rem; white-space: normal; }
#write .footnote-line { white-space: pre-wrap; }
@media print {
body, html { border: 1px solid transparent; height: 99%; break-after: avoid; break-before: avoid; }
#write { margin-top: 0px; padding-top: 0px; border-color: transparent !important; }
.typora-export * { -webkit-print-color-adjust: exact; }
html.blink-to-pdf { font-size: 13px; }
.typora-export #write { padding-left: 32px; padding-right: 32px; padding-bottom: 0px; break-after: avoid; }
.typora-export #write::after { height: 0px; }
}
.footnote-line { margin-top: 0.714em; font-size: 0.7em; }
a img, img a { cursor: pointer; }
pre.md-meta-block { font-size: 0.8rem; min-height: 0.8rem; white-space: pre-wrap; background: rgb(204, 204, 204); display: block; overflow-x: hidden; }
p > .md-image:only-child:not(.md-img-error) img, p > img:only-child { display: block; margin: auto; }
p > .md-image:only-child { display: inline-block; width: 100%; }
#write .MathJax_Display { margin: 0.8em 0px 0px; }
.md-math-block { width: 100%; }
.md-math-block:not(:empty)::after { display: none; }
[contenteditable="true"]:active, [contenteditable="true"]:focus { outline: 0px; box-shadow: none; }
.md-task-list-item { position: relative; list-style-type: none; }
.task-list-item.md-task-list-item { padding-left: 0px; }
.md-task-list-item > input { position: absolute; top: 0px; left: 0px; margin-left: -1.2em; margin-top: calc(1em - 10px); border: none; }
.math { font-size: 1rem; }
.md-toc { min-height: 3.58rem; position: relative; font-size: 0.9rem; border-radius: 10px; }
.md-toc-content { position: relative; margin-left: 0px; }
.md-toc-content::after, .md-toc::after { display: none; }
.md-toc-item { display: block; color: rgb(65, 131, 196); }
.md-toc-item a { text-decoration: none; }
.md-toc-inner:hover { text-decoration: underline; }
.md-toc-inner { display: inline-block; cursor: pointer; }
.md-toc-h1 .md-toc-inner { margin-left: 0px; font-weight: 700; }
.md-toc-h2 .md-toc-inner { margin-left: 2em; }
.md-toc-h3 .md-toc-inner { margin-left: 4em; }
.md-toc-h4 .md-toc-inner { margin-left: 6em; }
.md-toc-h5 .md-toc-inner { margin-left: 8em; }
.md-toc-h6 .md-toc-inner { margin-left: 10em; }
@media screen and (max-width: 48em) {
.md-toc-h3 .md-toc-inner { margin-left: 3.5em; }
.md-toc-h4 .md-toc-inner { margin-left: 5em; }
.md-toc-h5 .md-toc-inner { margin-left: 6.5em; }
.md-toc-h6 .md-toc-inner { margin-left: 8em; }
}
a.md-toc-inner { font-size: inherit; font-style: inherit; font-weight: inherit; line-height: inherit; }
.footnote-line a:not(.reversefootnote) { color: inherit; }
.md-attr { display: none; }
.md-fn-count::after { content: "."; }
code, pre, samp, tt { font-family: var(--monospace); }
kbd { margin: 0px 0.1em; padding: 0.1em 0.6em; font-size: 0.8em; color: rgb(36, 39, 41); background: rgb(255, 255, 255); border: 1px solid rgb(173, 179, 185); border-radius: 3px; box-shadow: rgba(12, 13, 14, 0.2) 0px 1px 0px, rgb(255, 255, 255) 0px 0px 0px 2px inset; white-space: nowrap; vertical-align: middle; }
.md-comment { color: rgb(162, 127, 3); opacity: 0.8; font-family: var(--monospace); }
code { text-align: left; vertical-align: initial; }
a.md-print-anchor { white-space: pre !important; border-width: initial !important; border-style: none !important; border-color: initial !important; display: inline-block !important; position: absolute !important; width: 1px !important; right: 0px !important; outline: 0px !important; background: 0px 0px !important; text-decoration: initial !important; text-shadow: initial !important; }
.md-inline-math .MathJax_SVG .noError { display: none !important; }
.html-for-mac .inline-math-svg .MathJax_SVG { vertical-align: 0.2px; }
.md-math-block .MathJax_SVG_Display { text-align: center; margin: 0px; position: relative; text-indent: 0px; max-width: none; max-height: none; min-height: 0px; min-width: 100%; width: auto; overflow-y: hidden; display: block !important; }
.MathJax_SVG_Display, .md-inline-math .MathJax_SVG_Display { width: auto; margin: inherit; display: inline-block !important; }
.MathJax_SVG .MJX-monospace { font-family: var(--monospace); }
.MathJax_SVG .MJX-sans-serif { font-family: sans-serif; }
.MathJax_SVG { display: inline; font-style: normal; font-weight: 400; line-height: normal; zoom: 90%; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; }
.MathJax_SVG * { transition: none 0s ease 0s; }
.MathJax_SVG_Display svg { vertical-align: middle !important; margin-bottom: 0px !important; margin-top: 0px !important; }
.os-windows.monocolor-emoji .md-emoji { font-family: "Segoe UI Symbol", sans-serif; }
.md-diagram-panel > svg { max-width: 100%; }
[lang="mermaid"] svg, [lang="flow"] svg { max-width: 100%; height: auto; }
[lang="mermaid"] .node text { font-size: 1rem; }
table tr th { border-bottom: 0px; }
video { max-width: 100%; display: block; margin: 0px auto; }
iframe { max-width: 100%; width: 100%; border: none; }
.highlight td, .highlight tr { border: 0px; }

.CodeMirror { height: auto; }
.CodeMirror.cm-s-inner { background: inherit; }
.CodeMirror-scroll { overflow: auto hidden; z-index: 3; }
.CodeMirror-gutter-filler, .CodeMirror-scrollbar-filler { background-color: rgb(255, 255, 255); }
.CodeMirror-gutters { border-right: 1px solid rgb(221, 221, 221); background: inherit; white-space: nowrap; }
.CodeMirror-linenumber { padding: 0px 3px 0px 5px; text-align: right; color: rgb(153, 153, 153); }
.cm-s-inner .cm-keyword { color: rgb(119, 0, 136); }
.cm-s-inner .cm-atom, .cm-s-inner.cm-atom { color: rgb(34, 17, 153); }
.cm-s-inner .cm-number { color: rgb(17, 102, 68); }
.cm-s-inner .cm-def { color: rgb(0, 0, 255); }
.cm-s-inner .cm-variable { color: rgb(0, 0, 0); }
.cm-s-inner .cm-variable-2 { color: rgb(0, 85, 170); }
.cm-s-inner .cm-variable-3 { color: rgb(0, 136, 85); }
.cm-s-inner .cm-string { color: rgb(170, 17, 17); }
.cm-s-inner .cm-property { color: rgb(0, 0, 0); }
.cm-s-inner .cm-operator { color: rgb(152, 26, 26); }
.cm-s-inner .cm-comment, .cm-s-inner.cm-comment { color: rgb(170, 85, 0); }
.cm-s-inner .cm-string-2 { color: rgb(255, 85, 0); }
.cm-s-inner .cm-meta { color: rgb(85, 85, 85); }
.cm-s-inner .cm-qualifier { color: rgb(85, 85, 85); }
.cm-s-inner .cm-builtin { color: rgb(51, 0, 170); }
.cm-s-inner .cm-bracket { color: rgb(153, 153, 119); }
.cm-s-inner .cm-tag { color: rgb(17, 119, 0); }
.cm-s-inner .cm-attribute { color: rgb(0, 0, 204); }
.cm-s-inner .cm-header, .cm-s-inner.cm-header { color: rgb(0, 0, 255); }
.cm-s-inner .cm-quote, .cm-s-inner.cm-quote { color: rgb(0, 153, 0); }
.cm-s-inner .cm-hr, .cm-s-inner.cm-hr { color: rgb(153, 153, 153); }
.cm-s-inner .cm-link, .cm-s-inner.cm-link { color: rgb(0, 0, 204); }
.cm-negative { color: rgb(221, 68, 68); }
.cm-positive { color: rgb(34, 153, 34); }
.cm-header, .cm-strong { font-weight: 700; }
.cm-del { text-decoration: line-through; }
.cm-em { font-style: italic; }
.cm-link { text-decoration: underline; }
.cm-error { color: red; }
.cm-invalidchar { color: red; }
.cm-constant { color: rgb(38, 139, 210); }
.cm-defined { color: rgb(181, 137, 0); }
div.CodeMirror span.CodeMirror-matchingbracket { color: rgb(0, 255, 0); }
div.CodeMirror span.CodeMirror-nonmatchingbracket { color: rgb(255, 34, 34); }
.cm-s-inner .CodeMirror-activeline-background { background: inherit; }
.CodeMirror { position: relative; overflow: hidden; }
.CodeMirror-scroll { height: 100%; outline: 0px; position: relative; box-sizing: content-box; background: inherit; }
.CodeMirror-sizer { position: relative; }
.CodeMirror-gutter-filler, .CodeMirror-hscrollbar, .CodeMirror-scrollbar-filler, .CodeMirror-vscrollbar { position: absolute; z-index: 6; display: none; }
.CodeMirror-vscrollbar { right: 0px; top: 0px; overflow: hidden; }
.CodeMirror-hscrollbar { bottom: 0px; left: 0px; overflow: hidden; }
.CodeMirror-scrollbar-filler { right: 0px; bottom: 0px; }
.CodeMirror-gutter-filler { left: 0px; bottom: 0px; }
.CodeMirror-gutters { position: absolute; left: 0px; top: 0px; padding-bottom: 30px; z-index: 3; }
.CodeMirror-gutter { white-space: normal; height: 100%; box-sizing: content-box; padding-bottom: 30px; margin-bottom: -32px; display: inline-block; }
.CodeMirror-gutter-wrapper { position: absolute; z-index: 4; background: 0px 0px !important; border: none !important; }
.CodeMirror-gutter-background { position: absolute; top: 0px; bottom: 0px; z-index: 4; }
.CodeMirror-gutter-elt { position: absolute; cursor: default; z-index: 4; }
.CodeMirror-lines { cursor: text; }
.CodeMirror pre { border-radius: 0px; border-width: 0px; background: 0px 0px; font-family: inherit; font-size: inherit; margin: 0px; white-space: pre; overflow-wrap: normal; color: inherit; z-index: 2; position: relative; overflow: visible; }
.CodeMirror-wrap pre { overflow-wrap: break-word; white-space: pre-wrap; word-break: normal; }
.CodeMirror-code pre { border-right: 30px solid transparent; width: fit-content; }
.CodeMirror-wrap .CodeMirror-code pre { border-right: none; width: auto; }
.CodeMirror-linebackground { position: absolute; left: 0px; right: 0px; top: 0px; bottom: 0px; z-index: 0; }
.CodeMirror-linewidget { position: relative; z-index: 2; overflow: auto; }
.CodeMirror-wrap .CodeMirror-scroll { overflow-x: hidden; }
.CodeMirror-measure { position: absolute; width: 100%; height: 0px; overflow: hidden; visibility: hidden; }
.CodeMirror-measure pre { position: static; }
.CodeMirror div.CodeMirror-cursor { position: absolute; visibility: hidden; border-right: none; width: 0px; }
.CodeMirror div.CodeMirror-cursor { visibility: hidden; }
.CodeMirror-focused div.CodeMirror-cursor { visibility: inherit; }
.cm-searching { background: rgba(255, 255, 0, 0.4); }
@media print {
.CodeMirror div.CodeMirror-cursor { visibility: hidden; }
}

:root { --side-bar-bg-color: #fafafa; --control-text-color: #777; }
html { font-size: 16px; }
body { font-family: "Open Sans", "Clear Sans", "Helvetica Neue", Helvetica, Arial, sans-serif; color: rgb(51, 51, 51); line-height: 1.6; }
#write { max-width: 860px; margin: 0px auto; padding: 30px 30px 100px; }
#write > ul:first-child, #write > ol:first-child { margin-top: 30px; }
a { color: rgb(65, 131, 196); }
h1, h2, h3, h4, h5, h6 { position: relative; margin-top: 1rem; margin-bottom: 1rem; font-weight: bold; line-height: 1.4; cursor: text; }
h1:hover a.anchor, h2:hover a.anchor, h3:hover a.anchor, h4:hover a.anchor, h5:hover a.anchor, h6:hover a.anchor { text-decoration: none; }
h1 tt, h1 code { font-size: inherit; }
h2 tt, h2 code { font-size: inherit; }
h3 tt, h3 code { font-size: inherit; }
h4 tt, h4 code { font-size: inherit; }
h5 tt, h5 code { font-size: inherit; }
h6 tt, h6 code { font-size: inherit; }
h1 { padding-bottom: 0.3em; font-size: 2.25em; line-height: 1.2; border-bottom: 1px solid rgb(238, 238, 238); }
h2 { padding-bottom: 0.3em; font-size: 1.75em; line-height: 1.225; border-bottom: 1px solid rgb(238, 238, 238); }
h3 { font-size: 1.5em; line-height: 1.43; }
h4 { font-size: 1.25em; }
h5 { font-size: 1em; }
h6 { font-size: 1em; color: rgb(119, 119, 119); }
p, blockquote, ul, ol, dl, table { margin: 0.8em 0px; }
li > ol, li > ul { margin: 0px; }
hr { height: 2px; padding: 0px; margin: 16px 0px; background-color: rgb(231, 231, 231); border: 0px none; overflow: hidden; box-sizing: content-box; }
li p.first { display: inline-block; }
ul, ol { padding-left: 30px; }
ul:first-child, ol:first-child { margin-top: 0px; }
ul:last-child, ol:last-child { margin-bottom: 0px; }
blockquote { border-left: 4px solid rgb(223, 226, 229); padding: 0px 15px; color: rgb(119, 119, 119); }
blockquote blockquote { padding-right: 0px; }
table { padding: 0px; word-break: initial; }
table tr { border-top: 1px solid rgb(223, 226, 229); margin: 0px; padding: 0px; }
table tr:nth-child(2n), thead { background-color: rgb(248, 248, 248); }
table tr th { font-weight: bold; border-width: 1px 1px 0px; border-top-style: solid; border-right-style: solid; border-left-style: solid; border-top-color: rgb(223, 226, 229); border-right-color: rgb(223, 226, 229); border-left-color: rgb(223, 226, 229); border-image: initial; border-bottom-style: initial; border-bottom-color: initial; text-align: left; margin: 0px; padding: 6px 13px; }
table tr td { border: 1px solid rgb(223, 226, 229); text-align: left; margin: 0px; padding: 6px 13px; }
table tr th:first-child, table tr td:first-child { margin-top: 0px; }
table tr th:last-child, table tr td:last-child { margin-bottom: 0px; }
.CodeMirror-lines { padding-left: 4px; }
.code-tooltip { box-shadow: rgba(0, 28, 36, 0.3) 0px 1px 1px 0px; border-top: 1px solid rgb(238, 242, 242); }
.md-fences, code, tt { border: 1px solid rgb(231, 234, 237); background-color: rgb(248, 248, 248); border-radius: 3px; padding: 2px 4px 0px; font-size: 0.9em; }
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html { font-size: 13px; }
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Python学习day09 - Python进阶(3)

异常处理

1. 什么是异常

异常其实就是我们平时写程序运行程序时的报错,在Python中,异常一般分为两类,即语法错误和逻辑错误

2. 语法错误

语法错误过不了python解释器的语法检测,所以在程序执行之前必须改正,否则程序无法正常执行。

常见如下例:

 
 
 
xxxxxxxxxx
4
 
 
 
 
1
if#SyntaxError: invalid syntax
2
3
0 = 1#SyntaxError: can't assign to literal
4
 
 

语法错误的错误类型基本都是SyntaxError,后面是较详细的描述。

3. 逻辑错误

逻辑错误不同于语法错误的是,其错误类型比较多样。比如:

 
 
 
xxxxxxxxxx
26
 
 
 
 
1
# TypeError:int类型不可迭代
2
for i in 3:
3
    pass
4
5
# ValueError
6
num=input(">>: ") #输入hello
7
int(num)
8
9
# NameError
10
aaa
11
12
# IndexError
13
l=['egon','aa']
14
l[3]
15
16
# KeyError
17
dic={'name':'egon'}
18
dic['age']
19
20
# AttributeError
21
class Foo:pass
22
Foo.x
23
24
# ZeroDivisionError:无法完成计算
25
res1=1/0
26
res2=1+'str'
 
 

4. 万能捕捉异常的方式

当然我们捕捉异常是为了发现,并处理异常,所以这里介绍一种万能的捕获异常的方法:

 
 
 
xxxxxxxxxx
5
 
 
 
 
1
s1 = 'hello'
2
try:
3
    int(s1)
4
except Exception as e:
5
    print(e)
 
 

Exception可以替代所有的异常类型用来赋值输出,非常方便。而实际上现在的解释器本身的报错,定位错误的功能都挺强大的,所以用这个功能比较有限。

Python深浅拷贝

一般Python的拷贝分为以下三种,我们分别介绍,用copy之前记得加上头文件import copy.

1. 拷贝(赋值)

赋值的常见方式如下:

 
 
 
xxxxxxxxxx
7
 
 
 
 
1
lt = [1, 2, 3]
2
lt2 = lt
3
print(lt)
4
print(lt2)
5
lt.append(4)
6
print(lt)
7
print(lt2)
 
 

[1,2,3]

[1,2,3]

[1,2,3,4]

[1,2,3,4]

 
 
 
xxxxxxxxxx
1
 
 
 
 
1
上述打印结果可以看到,lt的值变化,lt2的值也会跟着变化,这就是最一般的赋值
 
 

2. 浅拷贝

 
 
 
xxxxxxxxxx
6
 
 
 
 
1
# lt2没有变化的情况
2
lt = [1, 2, 3]
3
lt2 = copy.copy(lt)
4
lt.append(4)
5
print(lt)  # [1, 2, 3, 4] 
6
print(lt2)  # [1, 2, 3]
 
 

以上就是lt2没有跟随lt变化而变化,因为添加修改的是一个字符串,不是可变类型。

 
 
 
xxxxxxxxxx
6
 
 
 
 
1
# lt2变化的情况
2
lt = [1, 2, 3,[4,5,6]]
3
lt2 = copy.copy(lt)
4
lt[3].append(7)
5
print(lt)  # [1, 2, 3, [4,5,6,7]] 
6
print(lt2)  # [1, 2, 3,[4,5,6]]
 
 

该例就是lt2跟随lt变化的情况,因为往里面添加的是修改一个列表,是可变的类型。

3. 深拷贝

深拷贝是最稳定的拷贝,也是对原值保留最好的,永远不会随原值改变。

 
 
 
xxxxxxxxxx
15
 
 
 
 
1
t = [1000, 2000, 3000, [4000, 5000, 6000]]
2
print('id(lt)',id(lt))
3
print('id(lt[0])', id(lt[0]))
4
print('id(lt[1])', id(lt[1]))
5
print('id(lt[2])', id(lt[2]))
6
print('id(lt[3])', id(lt[3]))
7
print('*' * 50)
8
lt2 = copy.deepcopy(lt)
9
print('id(lt2)',id(lt2))
10
print('id(lt2[0])', id(lt2[0]))
11
print('id(lt2[1])', id(lt2[1]))
12
print('id(lt2[2])', id(lt2[2]))
13
print('id(lt2[3])', id(lt2[3]))
14
print('*' * 50)
15
 
 

由以上打印结果可以看出,不管lt怎么改变,lt2都不会随之改变。

  • 总结如下:
 
 
 
xxxxxxxxxx
8
 
 
 
 
1
# 牢记: 拷贝/浅拷贝/深拷贝 只针对可变数据类型
2
3
# 拷贝: 当lt2为lt的拷贝对象时,lt内的可变类型变化,lt2变化;lt内的不可变类型变化,lt2变化。 
4
5
#浅拷贝:当lt2为lt的浅拷贝对象时,lt内的可变类型变化,lt2变化;lt内的不可变类型变化,lt2不变化
6
7
# 深拷贝: 当lt2为lt的深拷贝对象时,lt内的可变类型变化,lt2不变化;lt内的不可变类型变化,lt2不变
8
 
 

基本的文件操作

什么是文件呢,之前的博客中有介绍,文件其实就是操作系统提供给用户的一个虚拟单位,是用来存储数据的。那么用Python来对文件操作有以下几个常用的操作。

1. 找到文件路径

 
 
 
xxxxxxxxxx
6
 
 
 
 
1
path = r'D:\Python学习\.idea\Python学习.iml'
2
3
# python里就是这样打开文件路径的,以上这种也叫做绝对路径。相对路径可以如下表示
4
path = r'Python学习.iml'
5
6
#相对路径即你所执行的这个py文件的当前文件夹,会默认在这里搜索
 
 

2. 双击打开

 
 
 
xxxxxxxxxx
3
 
 
 
 
1
f = open(path,'w',encoding = 'utf8')
2
print(f)
3
# r-->只读,w-->只写,清空当前文件后写入,后面的encoding为所打开文件的编码格式
 
 

3. 看文件

 
 
 
xxxxxxxxxx
2
 
 
 
 
1
data = f.read()
2
print(data)
 
 

4. 写文件

 
 
 
xxxxxxxxxx
1
 
 
 
 
1
f.write('fsfda')
 
 

5. 关闭文件

 
 
 
xxxxxxxxxx
4
 
 
 
 
1
del f 
2
f.close()
3
4
#需要注意的是,del f只是删除了解释器对文件的引用,并没有真正关闭文件,只有f.close才是真正的关闭文件
 
 

实战之猜年龄游戏

这是最近学习遇到的第一个稍有规模的代码,实现方式有很多种,以下两种仅供参考:

题目需求如下:

  1. 奖励物品存放在文件price.txt
  2. 给定年龄(随机18-60),用户可以猜三次年龄
  3. 年龄猜对,让用户选择两次奖励
  4. 用户选择两次奖励后可以退出
  • 常规猜年龄

     
     
     
    xxxxxxxxxx
    67
     
     
     
     
    1
    import random
    2
    3
    age = random.randint(18, 60)  # 随机一个数字,18-60岁
    4
    count = 0  # 计数
    5
    6
    f = open('price.txt', 'r', encoding='utf8')  # price.txt右下角为什么编码,则encoding为什么编码
    7
    price_dict = f.read()
    8
    price_dict = eval(price_dict)  # type:dict # 获取奖品字典
    9
    f.close()
    10
    11
    price_self = dict()
    12
    13
    while count < 3:
    14
        count += 1
    15
    16
        inp_age = input('请输入你想要猜的年龄:')
    17
    18
        # 判断是否为纯数字
    19
        if not inp_age.isdigit():
    20
            print('搞事就骂你傻逼')
    21
            continue
    22
    23
        inp_age = int(inp_age)
    24
    25
        # 筛选年龄范围
    26
        if inp_age > 60 or inp_age < 18:
    27
            print('好好题目,18-60岁,非诚勿扰')
    28
            continue
    29
    30
        # 核心逻辑
    31
        if age == inp_age:
    32
            print('猜中了,请选择你的奖品')
    33
    34
            # 打印商品
    35
            for k, v in price_dict.items():
    36
                print(f'奖品编号:{k} {v}')
    37
    38
            # 获取奖品的两次循环
    39
            for i in range(2):
    40
                price_choice = input('请输入你需要的奖品编号:')
    41
    42
                if not price_choice.isdigit():
    43
                    print("恭喜你已经获得一次奖品,奖品为空!并且请输入正确的奖品编号!")
    44
                    continue
    45
    46
                price_choice = int(price_choice)
    47
    48
                if price_choice not in price_dict:
    49
                    print('你想多了吧!')
    50
                else:
    51
                    price_get = price_dict[price_choice]
    52
                    print(f'恭喜中奖:{price_get}')
    53
    54
                    if price_self.get(price_get):
    55
                        price_self[price_get] += 1
    56
                    else:
    57
                        price_self[price_get] = 1
    58
    59
            print(f'恭喜你获得以下奖品:{price_self}')
    60
            break
    61
    62
        elif age > inp_age:
    63
            print('猜小了')
    64
        elif age < inp_age:
    65
            print('猜大了')
    66
    67
        continue
     
     
  • 抽奖式猜年龄

     
     
     
    xxxxxxxxxx
    1
    74
     
     
    1
    import random
    2
    3
    age = random.randint(18, 19)  # 随机一个数字,18-60岁
    4
    count = 0  # 计数
    5
    6
    f = open('price.txt', 'r', encoding='utf8')  # price.txt右下角为什么编码,则encoding为什么编码
    7
    price_dict = f.read()
    8
    price_dict = eval(price_dict)  # type:dict # 获取奖品字典
    9
    f.close()
    10
    11
    price_self = dict()
    12
    13
    while count < 3:
    14
        count += 1
    15
    16
        inp_age = input('请输入你想要猜的年龄:')
    17
    18
        # 判断是否为纯数字
    19
        if not inp_age.isdigit():
    20
            print('搞事就骂你傻逼')
    21
            continue
    22
    23
        inp_age = int(inp_age)
    24
    25
        # 筛选年龄范围
    26
        if inp_age > 60 or inp_age < 18:
    27
            print('好好题目,18-60岁,非诚勿扰')
    28
            continue
    29
    30
        # 核心逻辑
    31
        if age == inp_age:
    32
            print('猜中了,请选择你的奖品')
    33
    34
            # 打印商品
    35
            for k, v in price_dict.items():
    36
                print(f'奖品编号:{k} {v}')
    37
    38
            # 获取奖品的两次循环
    39
            for i in range(2):
    40
                price_y = input(f'请按"Y or y"转动转盘{chr(9803)}:').lower()
    41
    42
                if price_y != 'y':
    43
                    print("恭喜你已经获得一次奖品,奖品为空!并且请输入'Y or y'!")
    44
                    continue
    45
    46
                #
    47
                price_choice = random.randint(0, 10000)
    48
    49
                if price_choice > 0 and price_choice < 9900:
    50
                    price_choice = 6
    51
                    print('恭喜你, 下次一定有好东西!!', end=' ')
    52
                else:
    53
                    price_choice = price_choice % 7
    54
    55
                if price_choice not in price_dict:
    56
                    print('你想多了吧!')
    57
                else:
    58
                    price_get = price_dict[price_choice]
    59
                    print(f'恭喜中奖:{price_get}')
    60
    61
                    if price_self.get(price_get):
    62
                        price_self[price_get] += 1
    63
                    else:
    64
                        price_self[price_get] = 1
    65
    66
            print(f'恭喜你获得以下奖品:{price_self}')
    67
            break
    68
    69
        elif age > inp_age:
    70
            print('猜小了')
    71
        elif age < inp_age:
    72
            print('猜大了')
     
     
    73
    74
        continue
     
     

以上内容均借鉴于恩师nick的博客,希望大家都去借鉴,关注,点赞~

https://www.cnblogs.com/nickchen121/p/10718112.html

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