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python - 如何按列标题从csv中提取数据

问题描述

我有要分析和绘制图表的 csv 文件（制表符分隔）。我可以从文件中提取数据，但我更喜欢使用列标题名称而不是普通索引。

即代替：

freq_data = my_data[:,0]

我会使用类似的东西：

freq2_data=dataA['Freq']

这将只给我那一列数据，而顶部字段没有“nan”。我想这样做，以防某些人对数据的排序不同。

我目前拥有的是：

import os
import csv
import numpy as np
from numpy import genfromtxt

def mylistdir(directory):
    """A specialized version of os.listdir() that ignores files that
    start with a leading period."""
    filelist = os.listdir(directory)
    return [x for x in filelist
            if not (x.startswith('.'))]
path = ("C:\\Users\\priper\\Desktop\\rough_data\\")
results_files = mylistdir(path)
print(results_files)


vel_data = []

for f in results_files:
    f = path + f
    my_data = np.genfromtxt(f, dtype = float, delimiter='\t') #, names = True, max_rows=1
    print(my_data)
    freq_data = my_data[:,0]
    height_data = my_data[:,1]
    width_data = my_data[:,2]
    time_data = my_data[:,3]
    freq2_data=dataA['Freq']
    print(width_data)
    print(freq2_data)

关于我能做什么的任何想法？

.csv 文件：

Freqheight_cmsWidth_cmsTime_secs
"998.2121573301549  44.08897100772889   6.445672191528545   90.0"
"998.2121573301549  46.34952337794475   6.49171270718232    90.0"
"998.2121573301549  39.7907973252776    6.49171270718232    90.0"
"1999.404052443385  42.986804623146725  6.445672191528545   90.0"
"1999.404052443385  38.76177273904744   6.49171270718232    90.0"
"1999.404052443385  46.34952337794475   6.491875969369261   89.59365376669096"
"2997.61620977354   44.08897100772889   6.491875969369261   89.59365376669096"
"2997.61620977354   42.986804623146725  6.537915335317934   89.59651526494126"
"2997.61620977354   44.08897100772889   6.49171270718232    90.0"
"3998.80810488677   47.50820176059876   6.307550644567219   90.0"
"3998.80810488677   46.34952337794475   6.3535911602209945  90.0"
"3998.80810488677   41.903151251584184  6.3997972870975675  89.58780725859766"
"5000.0 38.76177273904744   6.21564013134898    89.57559458063852"
"5000.0 44.08897100772889   6.261510128913444   90.0"
"5000.0 41.903151251584184  6.2616793932272925  89.57871509583141"
"5998.212157330155  33.881963382336906  6.077522459688805   89.5659493678606"
"5998.212157330155  47.50820176059876   5.985444111277719   89.55927192723898"
"5998.212157330155  53.59203690324092   6.123388581952118   90.0"

这是在仔细阅读以下用户给出的答案和提示后起作用的。

for f in results_files:
    f = path + f
    data = pd.read_csv(f, sep = '\t')
    length_of_data = len(data)
    print(data.head(length_of_data))
    freqy = data[['Freq']]
    print(freqy)

标签： pythonnumpycsvdata-analysisgenfromtxt

解决方案

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