我如何 plot 多行使用 dataframe 上的值计数

Question

df.groupby('arrival_date_year').market_segment.value_counts()

I used the above code to get the following results:

arrival_date_year  market_segment
2015               Online TA          6165
                   Groups             6100
                   Offline TA/TO      6079
                   Direct             2314
                   Corporate          1171
                   Complementary       165
                   Undefined             2
2016               Online TA         27661
                   Offline TA/TO     12473
                   Groups             7857
                   Direct             5663
                   Corporate          2562
                   Complementary       364
                   Aviation            127
2017               Online TA         22651
                   Groups             5854
                   Offline TA/TO      5667
                   Direct             4629
                   Corporate          1562
                   Complementary       214
                   Aviation            110

What is the correct syntax to plot multiple lines representing the various market segments with x axis=year and y axis=value count ?

Alternatively, how do I get the data in wide format so that it's easier to compare the counts side by side?

Answer 1

To compare the counts side by side how about

df.groupby('arrival_date_year').market_segment.value_counts().unstack().reset_index()

eg

df
Out[257]: 
    X   Y    Z
0   a  10  100
1   b  20  200
2   a  30  300
3   b  10  400
4   a  20  100
5   b  30  200
6   a  10  300
7   b  20  400
8   a  30  100
9   b  10  200
10  a  20  300
11  b  30  400
df.groupby('X').Y.value_counts().unstack().reset_index()
Out[258]: 
Y  X  10  20  30
0  a   2   2   2
1  b   2   2   2