我有一个pandas数据框 tdf 我正在基于布尔标签提取切片
idx = tdf['MYcol1'] == 1
myslice = tdf.loc[idx] //I want myslice to be a view not a copy
现在我想填写 myslice 列中的缺失值，我希望这能反映在 tdf 我的原始数据框
中myslice.loc[:,'MYcol2'].fillna(myslice['MYcol2'].mean(), inplace = True) // 1
myslice.ix[:,'MYcol2'].fillna(myslice['MYcol2'].mean(), inplace = True) // 2
上面的1和2都抛出警告：正在尝试在DataFrame的切片副本上设置一个值
我做错了什么？
答案 0 :(得分：2)
将其分配给新变量时，会创建副本。你之后做的事情是无关紧要的。考虑一下：
myslice.is_copy
Out: <weakref at 0x000001CC842FD318; to 'DataFrame' at 0x000001CC8422D6A0>
填写NaN＆＃39;在myslice中：
tdf.loc[:, 'B'].fillna(tdf.loc[idx, 'B'].mean(), inplace=True)
tdf
Out:
A B C
0 NaN 0.195070 -1.781563
1 -0.729045 0.196557 0.354758
2 0.616887 0.008628 NaN
3 NaN 0.008628 0.037006
4 0.767902 0.008628 NaN
5 -0.805627 0.008628 NaN
6 1.133080 0.008628 -0.659892
7 -1.139802 0.784958 -0.554310
8 -0.470638 -0.216950 NaN
9 -0.392389 -3.046143 0.543312
它没有反映在tdf中，因为：
myslice['B'].mean()如果您将其更改为：
<div align="center" class="title">Statistiche:</div>
<div id="outer_container">
<div id="container">
<span class='multislider'>Hokuto ShinKen (<input type='text' required name='question_3' class='amount' value='5' data-min='0' data-max='100'/>)
<div class='slider tied'>
</div>
Nanto (<input type='text' required name='question_3' class='amount' value='15' data-min='0' data-max='100'/>)
<div class='slider tied'>
</div>
Gento (<input type='text' required name='question_3' class='amount' value='50' data-min='0' data-max='100'/>)
<div class='slider tied'>
</div>
Artiglio del Monte Taishan (<input type='text' required name='question_3' class='amount' value='30' data-min='0' data-max='100'/>)
<div class='slider tied'></div>
</span>
</div>
</div>
然后它的工作原理。在最后一部分中，您还可以使用 var init = true;
var elements = $(".multislider").children(".slider.tied").length;
var MAX = 100;
var inpVal = $('.txt_name').val();
var initValue = (inpVal) >> 0;
//var initValue = (MAX / elements) >> 0;
var InitMod = MAX % elements;
$(".slider.tied").each(function() {
var slidersTied = $(".slider.tied");
var context = $(this);
var input = context.prev(".amount");
var val = input.data('answer');
var min = input.data('min');
var max = input.data('max');
var range = 1;
var proceed = false;
$(this).empty().slider({
value: val,
min: min,
max: max,
range: range,
animate: "slow",
create: function(event, ui){
if (InitMod > 0) {
$(this).slider('value', initValue + 1);
$(this).prev('.amount').val(initValue + 1);
InitMod = InitMod - 1;
}
else
{
$(this).slider('value', initValue);
$(this).prev('.amount').val(initValue);
}
},
slide: function(e, ui) {
// Update display to current value
$(this).prev('.amount').val(ui.value);
var current = ($(this).index() / 2) >> 0;
var total = 0;
var counter = 0
slidersTied.not(this).each(function() {
total += $(this).slider("option", "value");
counter += 1;
});
total += ui.value;
if (total != MAX){
proceed = true;
}
var missing = MAX - total;
console.log("missing: " + missing);
counter = 0;
if(proceed) {
//carico vettore elementi
var elements = [];
slidersTied.each(function() {
elements[counter] = $(this);
counter += 1;
});
var endIndex = counter - 1;
counter = endIndex + 1;
while (missing != 0) {
console.log("current counter: " + counter);
do {
if (counter == 0)
{
counter = endIndex;
}
else
{
counter = counter - 1;
}
} while(counter == current)
console.log("elemento attuale: " + counter);
var value = elements[counter].slider("option", "value");
var result = value + missing;
if (result >= 0)
{
elements[counter].slider('value', result);
elements[counter].prev('.amount').val(result);
missing = 0;
}
else
{
missing = result;
elements[counter].slider('value', 0);
elements[counter].prev('.amount').val(0);
}
}
}
}
});
});
，因为您没有更新这些值。但左侧应该是原始的DataFrame。