保留两个小数点：

oninput="value=value.replace(/[^\d.]/g, '').replace(/\.{2,}/g, '.').replace('.', '$##39;).replace(/\./g, '').replace('$##39;, '.').replace(/^(\-)*(\d+)\.(\d\d).*$/, '$1$2.$3').replace(/^\./g, '')"

保留三位小数点：

oninput="value=value.replace(/[^\d.]/g, '').replace(/\.{2,}/g, '.').replace('.', '$##39;).replace(/\./g, '').replace('$##39;, '.').replace(/\D*(\d*)(\.?)(\d{0,3})\d*/,'$1$2$3').replace(/^\./g, '')"

只能输入数字0-9

<el-input
placeholder="请输入内容"
v-model="maintainPeriod"
oninput="value=value.replace(/[^\d]/g,'')"
maxlength="2">
</el-input>

转载：https://blog.csdn.net/qq_49781990/article/details/128542509