来自csv文件的Python条形图

Question

我有一个csv文件如下：

Statistic,Evap_a_lm,Evap_am,Evap_lm,Evap_od
STD_ctessel:,0.553843,0.572184,0.546684,0.568511
STD_htessel:,0.761471,0.938552,0.747172,0.919918
Mean_Bias_ctessel:,-0.290104,-0.248983,-0.310019,-0.267554
Mean_Bias_htessel:,-0.214769,-0.0868161,-0.233181,-0.103245

从这个CSV文件中我想迭代索引和行名称组件以生成条形图，如下所示：

为此，我确实生成了以下代码：

import os,sys,math,time
import csv
from matplotlib import rc
from matplotlib import pyplot as plt
from matplotlib import patches as mpatches
import numpy as np
import pandas as pd
variables = ["Evap"]
names = ["od", "lm", "am", "a_lm"]
models = ["ctessel", "htessel"]
statistics = ['STD']
for variable in variables:
    for name in names:
        data = pd.read_csv("merged.txt", delimiter='\t')
        data.set_index('Statistic')
        for stat in statistics:
            for model in models:
                od = data.loc[[stat + "_" + model + ":"],[variable + "_od"]].astype(float)
                lm = data.loc[[stat + "_" + model + ":"],[variable + "_lm"]].astype(float)
                am = data.loc[[stat + "_" + model + ":"],[variable + "_am" + station]].astype(float)
                a_lm = data.loc[[stat + "_" + model + ":"],[variable + "_a_lm" + station]].astype(float)
                plt.title(variable + " " + stat, y=1.02)
                r1 = [1]
                r2 = [2]
                r3 = [3]
                r4 = [4]
                plt.bar(r1, od, width = barWidth, color="green", label='Original input')
                plt.bar(r2, lm, width = barWidth, color="yellow", label='Modis LAI')
                plt.bar(r3, am, width = barWidth, color="red", label='Modis Albedo')
                plt.bar(r4, a_lm, width = barWidth, color="blue", label='Modis LAI')
plt.savefig(outdir + station + "_" + "perf.pdf")

但不幸的是它不起作用，我总是有错误消息，显然它无法将标题的字符串转换为float：

ValueError: could not convert string to float: 'Evap_od'

有谁知道解决方法？

Answer 1

这应解决您的大部分问题。使用pandas可以避免所有额外的代码。然后，您可以从此处根据需要对其进行格式化。

import pandas as pd
import matplotlib.pyplot as plt

df = pd.read_csv('merged.txt')
df = df.set_index('Statistic')


fig, ax = plt.subplots()

df.plot(kind='bar', ax=ax)

ax.grid(color='gray', linestyle='-', alpha=0.3)

Example Plot