Question

我有一个数据框，其中一个col int一个col浮动：

.menu-device {
  position: relative;
  width: 100%;
  height: 95px;
  background-color: #FFF;
  -webkit-box-shadow: 0px 0px 15px -2px rgba(0, 0, 0, 0.75);
  -moz-box-shadow: 0px 0px 15px -2px rgba(0, 0, 0, 0.75);
  box-shadow: 0px 0px 15px -2px rgba(0, 0, 0, 0.75);
  z-index: 1000;
}

.menu-device .menu__button {
  text-align: center;
  margin-top: 37px;
  width: 105px;
  height: 58px;
  float: right;
}

.menu-device .menu-device__menu {
  width: 282px;
  border: 1px solid #ddd;
  display: none;
  position: absolute;
  top: 95px;
  right: 0;
  box-shadow: -3px 0 10px #ababab inset;
}

.menu-device .menu-device__menu .menu-device__item {
  background-image: url("../../img/menu_icon.png");
  background-position: right center;
  background-repeat: no-repeat;
  position: relative;
  line-height: 35px;
  padding-right: 30px;
  border-bottom: 1px solid #e5e5e5;
  background-color: #FFF;
  width: 252px;
  height: 35px;
  float: right;
  text-align: right;
}

.menu-device .menu-device__menu .menu-device__item .menu__link {
  color: #494949;
  text-decoration: none;
  font-size: 16px;
}

.menu-device .menu-device__menu .menu-device__item .submenu {
  background-color: #FFF;
  position: absolute;
  left: 0;
  top: 35px;
  display: none;
}

.menu-device .menu-device__menu .menu-device__item .submenu .submenu__item {
  line-height: 35px;
  padding-right: 30px;
  background-color: #FFF;
  width: 252px;
  height: 35px;
  float: right;
  text-align: right;
}

.menu-device .menu-device__menu .menu-device__item .submenu .submenu__item .submenu__link {
  font-size: 14px;
  text-decoration: none;
  color: #494949;
}

.menu-device .menu-device__menu .menu-device__item .submenu .submenu__item:hover {
  background-color: #a90027;
}

.menu-device .menu-device__menu .menu-device__item .submenu .submenu__item:hover .submenu__link {
  color: #fff;
}

.menu-device .menu-device__menu .menu-device__item:nth-child(1),
.menu-device .menu-device__menu .menu-device__item:nth-child(3),
.menu-device .menu-device__menu .menu-device__item:nth-child(6) {
  background-image: none;
}

.menu-device .menu-device__menu .menu-device__item:hover {
  background-color: #a90027;
}

.menu-device .menu-device__menu .menu-device__item:hover .menu__link {
  color: #fff;
}

.menu-device .menu__logo {
  position: absolute;
  float: left;
  width: 135px;
  margin-left: 91px;
  z-index: 2000;
}

.menu-device .menu__logo img {
  margin-top: -20px;
  max-width: 100%;
}

我想要一个像<script src="https://code.jquery.com/jquery-3.0.0.min.js"></script> <nav class="menu-device"> <div class="menu__button"> <a class="menu__pic" href="#"><img src="img/responsive_nav.png" alt="expand"></a> <ul class="menu-device__menu"> <li class="menu-device__item"><a href="#" class="menu__link">Menu Item</a></li> <li class="menu-device__item"><a href="#" class="menu__link">Menu Item</a> <ul class="submenu"> <li class="submenu__item"><a href="" class="submenu__link">Menu Item</a></li> <li class="submenu__item"><a href="" class="submenu__link">Menu Item</a></li> <li class="submenu__item"><a href="" class="submenu__link">Menu Item</a></li> <li class="submenu__item"><a href="" class="submenu__link">Menu Item</a></li> <li class="submenu__item"><a href="" class="submenu__link">Menu Item</a></li> <li class="submenu__item"><a href="" class="submenu__link">Menu Item</a></li> </ul> </li> <li class="menu-device__item"><a href="#" class="menu__link">Menu Item</a></li> <li class="menu-device__item"><a href="#" class="menu__link">Menu Item</a> <ul class="submenu"> <li class="submenu__item"><a href="" class="submenu__link">Menu Item</a></li> <li class="submenu__item"><a href="" class="submenu__link">Menu Item</a></li> </ul> </li> <li class="menu-device__item"><a href="#" class="menu__link">Menu Item</a> <ul class="submenu"> <li class="submenu__item"><a href="" class="submenu__link">Menu Item</a></li> </ul> </li> <li class="menu-device__item"><a href="#" class="menu__link">Menu Item</a></li> </ul> </div> </nav>

提供的那样的词典列表

df
#    a      b
# 0  3  42.00
# 1  2   3.14

df.dtypes
# a      int64
# b    float64
# dtype: object

但是df.to_dict(orient='records')为df.to_dict(orient='records') [{'a': 3.0, 'b': 42.0}, {'a': 2.0, 'b': 3.1400000000000001}]，而不是作为浮动

Answer 1

目前（从Pandas版本0.18开始），df.to_dict('records')访问NumPy数组df.values。此属性将int列的dtype向上转换为float，以便阵列可以具有单个公共dtype。在此之后，没有希望返回所需的结果 - 所有的整数都已转换为浮点数。

相反，在ayhan's和Tom Augspurger's suggestion的基础上，您可以使用列表和词典理解：

import pandas as pd

df = pd.DataFrame({'a':[3,2], 'b':[42.0,3.14]})
result = [{col:getattr(row, col) for col in df} for row in df.itertuples()]
print(result)
# [{'a': 3, 'b': 42.0}, {'a': 2, 'b': 3.1400000000000001}]

Answer 2

另一个可怕的解决方法是（暂时）添加非数字列，例如从：

开始

df = pd.DataFrame([[1, 2.4], [3, 4.0]], columns='a b'.split())

然后df.to_dict(orient='record')促进浮动，但如果你这样做：

df['foo'] = 'bar'
[{k: v for (k, v) in row.items() if k != 'foo'} for row in df.to_dict(orient='record')]

保留原始类型。我注意到df.reindex()行为相似，如Pandas gotchas中所述，但除非您填写非零值，否则无法解决问题，例如fill_value=0

使用orient ='records'获取python pandas to_dict但没有浮动转换

2 个答案: