Python 如何从文本文件创建值

首先我要说的是，我是python的超初学者，这也是我在这里的第一篇文章，因此，非常感谢对python的建设性批评。所以我得到了一个任务，我需要从一个文本文件中获取一些值，并从中列出一个列表，但我不知道如何做到这一点。 文本文件如下所示：

temperatuur 20.8 10.4
vochtigheid 70 14
windrichting Z 60
windkracht 6 60
temperatuur 21.8 10.9
vochtigheid 60 12
windrichting Z 60
windkracht 4 40
temperatuur 21.8 10.9
vochtigheid 60 12
windrichting Z 60
windkracht 5 50
temperatuur 21.8 10.9
vochtigheid 60 12
windrichting ZZW 50
windkracht 5 50
temperatuur 22.0 11.0
vochtigheid 60 12
windrichting ZZW 50
windkracht 5 50
temperatuur 22.2 11.1
vochtigheid 65 13
windrichting ZZW 50
windkracht 5 50
temperatuur 22.6 11.3
vochtigheid 70 14
windrichting ZZW 50
windkracht 5 50
temperatuur 22.8 11.4
vochtigheid 60 12
windrichting ZZW 50
windkracht 4 40
temperatuur 23.0 11.5
vochtigheid 60 12
windrichting ZZW 50
windkracht 4 40
temperatuur 23.0 11.5
vochtigheid 60 12
windrichting ZZW 50
windkracht 3 30
temperatuur 24.0 12.0
vochtigheid 60 12
windrichting Z 60
windkracht 3 30
temperatuur 25.0 12.5
vochtigheid 60 12
windrichting Z 60
windkracht 2 20
temperatuur 26.0 13.0
vochtigheid 60 12
windrichting Z 60
windkracht 2 20
temperatuur 27.0 13.5
vochtigheid 60 12
windrichting Z 60
windkracht 2 20
temperatuur 27.0 13.5
vochtigheid 60 12
windrichting Z 60
windkracht 2 20
temperatuur 25.0 12.5
vochtigheid 60 12
windrichting Z 60
windkracht 3 30
temperatuur 21.0 10.5
vochtigheid 75 15
windrichting W 40
windkracht 5 50
temperatuur 19.0 9.5
vochtigheid 75 15
windrichting W 40
windkracht 5 50
temperatuur 18.0 9.0
vochtigheid 75 15
windrichting W 40
windkracht 5 50
temperatuur 18.0 9.0
vochtigheid 75 15
windrichting W 40
windkracht 5 50
temperatuur 17.0 8.5
vochtigheid 80 16
windrichting W 40
windkracht 6 60
temperatuur 16.5 8.25
vochtigheid 80 16
windrichting W 40
windkracht 6 60
temperatuur 14.0 7.0
vochtigheid 80 16
windrichting W 40
windkracht 6 60
temperatuur 10.0 5.0
vochtigheid 80 16
windrichting W 40
windkracht 6 60

文本文件名为weerstation.txt。 正如你所见，它被分成4块，标签是温度、湿度、风向和风速。这些标签会重复24次，因为它们在一整天中每小时都会被贴上一次。 任务是仅获取荷兰语标签temperatuur temperature的值，并从中列出一个列表，并将该列表保存在单独的文本文件中。第一个值是以摄氏度为单位的温度，第二个值是以毫伏为单位的相关电压

第二个赋值是生成一个图形，读取先前创建的文本文件（即第一个赋值中创建的文本文件），并从中生成一个图形。x轴表示小时，y轴表示摄氏温度值

我一个人走了这么远：

L=[]
lista = []
listadef = []

with open('weerstation.txt') as f:
        for temperatuur in f:
            L.append(temperatuur)
# I used the next line just to see if it went allright and then left it there in case I need it again
#        print(L)

a = 0
while (a < len(L)):
    lista = L[a]
    listadef.append(lista)
    lista = []
    a = a+4 #I knew that the "temperatuur label" repeats itself after every 4 lines so that's why i took that route 


print(listadef)

正如你所看到的，这并不多。

---

有人能帮我清楚地解释一下你做了什么吗，亲爱的：

如果你只想读以“temperatuur”开头的行：

with open('weerstation.txt') as f:
    L = [line for line in f.readlines() if line.startswith('temperatuur')]

如果要将诸如“temperatuur 20.8 10.4”之类的行拆分为三个值，请使用拆分函数，但不要忘记value1和value2将是字符串，如果要创建图形，则必须将它们转换为数字：

label, value1, value2 = line.split()

您可以使用该模块读取文本文件，并使用该模块绘制所需的图形。更多细节可以在下面的代码中看到

import fileinput

temp_values = []
for line in fileinput.input("weerstation.txt"):
    print line, type(line)
    if 'temperatuur' in line:
        temp_values.append(line.strip().split()[1])  # split the list and just add the temperature

with open("temp_values.txt", "w") as fp:
    fp.write("\n".join(temp_values))                 # save values to temp_values.txt and finish assignment 1

print temp_values
# ['10.4', '10.9', '10.9', '10.9', '11.0', '11.1', '11.3', '11.4', '11.5', '11.5', '12.0', '12.5', '13.0', '13.5', '13.5', '12.5', '10.5', '9.5', '9.0', '9.0', '8.5', '8.25', '7.0', '5.0']


import matplotlib.pyplot as plt                     # using matplotlib to draw figure and finish assignment 2

plt.plot([i for i in xrange(0, 24)], temp_values)
plt.xlabel("Hours")
plt.ylabel("Temperatures")
plt.show()

---

请一次只问一个问题。专注于创建一个非常清晰的问题陈述。我忘了在第一次作业中，我需要列出度数和mV值，并将其保存到一个文本文件中。然后我读了那个文本文件来绘制图表。我现在了解了如何获取这两个值并将它们放入文本文件中，但如何只读取第一个值来制作图形？要读取temp_values.txt，还可以使用fileinput.input函数，对于文本文件中的每一行，只需拆分该行并保留第一个值。该过程可以简化为values=[line.split[1]for line in fileinput.inputtemp_values.txt]

import fileinput

temp_values = []
for line in fileinput.input("weerstation.txt"):
    print line, type(line)
    if 'temperatuur' in line:
        temp_values.append(line.strip().split()[1])  # split the list and just add the temperature

with open("temp_values.txt", "w") as fp:
    fp.write("\n".join(temp_values))                 # save values to temp_values.txt and finish assignment 1

print temp_values
# ['10.4', '10.9', '10.9', '10.9', '11.0', '11.1', '11.3', '11.4', '11.5', '11.5', '12.0', '12.5', '13.0', '13.5', '13.5', '12.5', '10.5', '9.5', '9.0', '9.0', '8.5', '8.25', '7.0', '5.0']


import matplotlib.pyplot as plt                     # using matplotlib to draw figure and finish assignment 2

plt.plot([i for i in xrange(0, 24)], temp_values)
plt.xlabel("Hours")
plt.ylabel("Temperatures")
plt.show()