小编prm*_*lmu的帖子

我有以下简单的数据框架

import pandas as pd
df = pd.DataFrame({'column_a': ['a', 'b', 'c', 'd', 'e'],
                   'column_b': ['b', 'x', 'y', 'c', 'z']})


      column_a column_b
0        a        b
1        b        x
2        c        y
3        d        c
4        e        z

我想要显示两列中出现的字符串:

result = ("b", "c")

谢谢

抱歉，如果已经有人问过我，但我找不到任何答案。我想在plt图上添加一条总体趋势线。样本数据：

import pandas as pd
data = pd.DataFrame({'year': [2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 
                              2019],
                     'value': [2, 5, 8, 4, 1, 6, 10, 14, 8]})

import matplotlib.pyplot as plt
plt.rcParams['figure.figsize'] = [28, 26]
data.plot(x = "year", y = "value", fontsize = 30)
plt.xlabel('Time', fontsize = 30)

如何添加趋势线？

I am drawing some grouped histograms in python as per this question, but am trying to plot more histograms and make them bigger.

To give an example:

from pandas import DataFrame
import numpy as np
x = ['A']*300 + ['B']*400 + ['C']*300 + ['D']*400 + ['E']*200 + ['F']*500 + 
['G']*400 + ['H']*500 + ['I']*300
y = np.random.randn(3300)
df = DataFrame({'Letter':x, 'N':y})
grouped = df.groupby('Letter')

I then plot like this in Jupyter:

%matplotlib inline
df['N'].hist(by=df['Letter'])

but the plots come out …