使用 pandas 或其他 python 模块读取特定列 [英] Read specific columns with pandas or other python module

问题描述

我有一个来自这个网页.我想读取下载文件中的一些列(可以在右上角下载csv版本).

I have a csv file from this webpage. I want to read some of the columns in the downloaded file (the csv version can be downloaded in the upper right corner).

假设我想要 2 列:

• 59 在标题中是 star_name
• 60 在标题中是 ra.

但是，出于某种原因，网页的作者有时会决定移动列.

However, for some reason the authors of the webpage sometimes decide to move the columns around.

最后我想要这样的东西，记住值可能会丢失.

In the end I want something like this, keeping in mind that values can be missing.

data = #read data in a clever way
names = data['star_name']
ras = data['ra']

如果它们保持名称正确，这将防止我的程序在将来再次更改列时出现故障.

This will prevent my program to malfunction when the columns are changed again in the future, if they keep the name correct.

到目前为止，我已经尝试了各种使用 csv 模块的方法，并且非常讨厌 pandas 模块.两者都没有运气.

Until now I have tried various ways using the csv module and resently the pandas module. Both without any luck.

编辑(添加了两行 + 我的数据文件的标题.抱歉，它太长了.)

EDIT (added two lines + the header of my datafile. Sorry, but it's extremely long.)

<代码>#名称，质量，mass_error_min，mass_error_max，半径，radius_error_min，radius_error_max，orbital_period，orbital_period_err_min，orbital_period_err_max，semi_major_axis，semi_major_axis_error_min，semi_major_axis_error_max，偏心，eccentricity_error_min，eccentricity_error_max，angular_distance，倾斜度，inclination_error_min，inclination_error_max，tzero_tr，tzero_tr_error_min，tzero_tr_error_max，tzero_tr_sec，tzero_tr_sec_error_min，tzero_tr_sec_error_max，lambda_angle，lambda_angle_error_min，lambda_angle_error_max，impact_parameter，impact_parameter_error_min，impact_parameter_error_max，tzero_vr，tzero_vr_error_min，tzero_vr_error_max，K，K_error_min，K_error_max，temp_calculated，temp_measured，hot_point_lon，反照率，albedo_error_min，albedo_error_max，log_g，publication_status，发现, 更新, 欧米茄, omega_error_min, omega_error_max, tperi, tperi_error_min, tperi_error_max, detection_type, mass_detection_type,radius_detection_type,alternate_names,分子，star_name，ra，dec，mag_v，mag_i，mag_j，mag_h，mag_k，star_distance，star_metality，star_mass，star_radius，star_sp_type，star_age，star_teff，star_detected_disc，star_magnetic_field11 Com b,19.4,1.5,1.5,,,,,326.03,0.32,0.32,1.29,0.05,0.05,0.231,0.005,0.005,0.011664,,,,,,,,,,,,,,,,,,,,,,,,,,1,2008,2011-12-23,94.8,1.5,1.5,2452899.6,1.6,1.6,径向速度,,,,,11 Com,185.1791667,17.792.747,17.792.747,,,110.6,-0.35,2.7,19​​.0,G8 III,,,4742.0,,11 UMi b,10.5,2.47,2.47,,,,,516.22,3.25,3.25,1.54,0.07,0.07,0.08,0.03,0.03,0.012887,,,,,,,,,,,,,,,,,,,,,,,,,,,1,2009,2009-08-13,117.63,21.06,21.06,2452861.05,2.06,2.06,径向速度,,,,,11 UMi,229.275,3,809.,119.5,0.04,1.8,24.08,K4III,1.56,4340.0,,

推荐答案

一个简单的方法是使用这样的 pandas 库.

An easy way to do this is using the pandas library like this.

import pandas as pd
fields = ['star_name', 'ra']

df = pd.read_csv('data.csv', skipinitialspace=True, usecols=fields)
# See the keys
print df.keys()
# See content in 'star_name'
print df.star_name

这里的问题是 skipinitialspace 删除了标题中的空格.所以'star_name'变成了'star_name'

The problem here was the skipinitialspace which remove the spaces in the header. So ' star_name' becomes 'star_name'

这篇关于使用 pandas 或其他 python 模块读取特定列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！