Question

使用这段代码，我得到了温度和日期时间，然后使用numpy（np）将它们插入到matplotlib（plt）

# get date times and the temperatures of a certain city, info pulled from request
raw_date_times = [item['dt_txt'] for item in s['list']]
temperature_kelvins = [item['main']['temp'] for item in s['list']]

# Apply calculation on each item to make celsius from kelvins
temperatures = [round(item - 273.15) for item in temperature_kelvins]

# Filter out today's date from list of dates into date_times
today = datetime.today().date()
date_times = []
for i in raw_date_times:
    date =  datetime.strptime(i, '%Y-%m-%d %H:%M:%S').date()
    if date == today:
        date_times.append(i)

# Convert the array with integers of temperatures to strings to make both of same dimension
for i in range(0, len(temperatures)): 
    temperatures[i] = str(temperatures[i]) 

# get len of date_times and convert it into an array (i.e 6 becomes [0,1,2,3,4,5])
date_times_len = len(date_times)
    n = []
for i in range(0,date_times_len):
n.append(i)
            print (n)

# Plot out map using values
x = np.array(n)
y = np.array([temperatures])
my_xticks = [date_times]
plt.xticks(x, my_xticks)
plt.plot(x, y)
plt.show()


# date_times example = ['2020-03-17 12:00:00', '2020-03-17 15:00:00', '2020-03-17 18:00:00', '2020-03-17 21:00:00']
# temperatures example (before string)= [29, 31, 30, 25, 23, 22, 20, 23, 30, 33, 31, 27, 24, 23, 21, 23, 31]

但是我一直收到此错误：

    for val in OrderedDict.fromkeys(data):
TypeError: unhashable type: 'numpy.ndarray'

我研究了一下，发现这意味着我认为形状有问题。是因为它们是字符串吗？如果是这样，那么您能建议一种将我的日期时间转换为整数的方法吗？

谢谢！

完整追溯：

Traceback (most recent call last):
  File "class-test.py", line 77, in <module>
    weatherData('gurgaon')
  File "class-test.py", line 55, in weatherData
    plt.plot(x, y)
  File "/Users/Ronnie/.local/share/virtualenvs/weather-d3bb5uZO/lib/python3.8/site-packages/matplotlib/pyplot.py", line 2761, in plot
    return gca().plot(
  File "/Users/Ronnie/.local/share/virtualenvs/weather-d3bb5uZO/lib/python3.8/site-packages/matplotlib/axes/_axes.py", line 1646, in plot
    lines = [*self._get_lines(*args, data=data, **kwargs)]
  File "/Users/Ronnie/.local/share/virtualenvs/weather-d3bb5uZO/lib/python3.8/site-packages/matplotlib/axes/_base.py", line 216, in __call__
    yield from self._plot_args(this, kwargs)
  File "/Users/Ronnie/.local/share/virtualenvs/weather-d3bb5uZO/lib/python3.8/site-packages/matplotlib/axes/_base.py", line 339, in _plot_args
    self.axes.yaxis.update_units(y)
  File "/Users/Ronnie/.local/share/virtualenvs/weather-d3bb5uZO/lib/python3.8/site-packages/matplotlib/axis.py", line 1516, in update_units
    default = self.converter.default_units(data, self)
  File "/Users/Ronnie/.local/share/virtualenvs/weather-d3bb5uZO/lib/python3.8/site-packages/matplotlib/category.py", line 107, in default_units
    axis.set_units(UnitData(data))
  File "/Users/Ronnie/.local/share/virtualenvs/weather-d3bb5uZO/lib/python3.8/site-packages/matplotlib/category.py", line 175, in __init__
    self.update(data)
  File "/Users/Ronnie/.local/share/virtualenvs/weather-d3bb5uZO/lib/python3.8/site-packages/matplotlib/category.py", line 210, in update
    for val in OrderedDict.fromkeys(data):
TypeError: unhashable type: 'numpy.ndarray'
(weather) bash-3.2$

Answer 1

也许这可以帮助

#first import
from datetime import datetime

a = datetime.now()
#converting into int 
a = int(a.strftime('%Y-%m-%d %H:%M:%S'))  #using strtime to convert datetime into int

Answer 2

是的，您可以使用字符串制作图形，但matplot版本应为> 2.1或2.2

import matplotlib.pyplot as plt
x = ["ABCD", "EEEEE", "LLLL"]
y = [5,2,3]

plt.plot(x, y)

plt.show()

Answer 3

我认为这可以复制部分情节：

In [347]: date_times = ['2020-03-17 12:00:00', '2020-03-17 15:00:00', '2020-03-17 18:00:00', '2020-03-17 21:00:00'] 
     ...: temperatures = [29, 31, 30, 25, 23, 22, 20, 23, 30, 33, 31, 27, 24, 23, 21, 23, 31]                        
In [348]: len(date_times)                                                                                            
Out[348]: 4
In [349]: len(temperatures)                                                                                          
Out[349]: 17
In [350]: x = np.arange(len(date_times))                                                                             
In [351]: y = np.array(temperatures[:4])    
In [359]: plt.xticks(x, date_times);                                                                                 
In [360]: plt.plot(x,y);

我的arange是构建x的一种比您更快捷的方法：

In [361]: n = [] 
     ...: for i in range(0,4): 
     ...:     n.append(i) 
     ...: np.array(n)

请注意，我使用的是date_times，而不是[date_times]；稍后会添加一个额外的列表层。我无法重现您的错误，但是不必要的[]可能会引起问题。 ticks的{{1}}和labels参数应具有相同的长度。

该错误看起来像是在创建轴（xticks）时发生的。它使用数组（xticks？）作为字典键。该错误在x代码的深处发生，因此很难将其追溯到您的输入。因此，仅检查输入（plt，x，y）并确保它们看起来合理（期望的数据和匹配的长度）就容易得多。

这里有同样的错误：

TypeError: unhashable type: 'numpy.ndarray' when trying to plot a DataFrame

尽管没有，但我看不出有什么相似或不同之处。

===

这可以确定：

date_times

但这会产生错误：

In [364]: plt.plot(date_times,y);

（与您的In [365]: plt.plot([date_times],y);一样，它有不必要的括号）。

尝试使用numpy进行绘图时，TypeError：不可哈希类型：numpy.ndarray

3 个答案: