Transpose and widen Data - python

My panda data frame looks like as follows:
Country Code 1960 1961 1962 1963 1964 1965 1966 1967 1968 ... 2015
ABW 2.615300 2.734390 2.678430 2.929920 2.963250 3.060540 ... 4.349760
AFG 0.249760 0.218480 0.210840 0.217240 0.211410 0.209910 ... 0.671330
ALB NaN NaN NaN NaN NaN NaN NaN NaN NaN ... 1.12214
...
How can I transpose it that it looks like as follows?
Country_Code Year Econometric_Metric
ABW 1960 2.615300
ABW 1961 2.734390
ABW 1962 2.678430
...
ABW 2015 4.349760
AFG 1960 0.249760
AFG 1961 0.218480
AFG 1962 0.210840
...
AFG 2015 0.671330
ALB 1960 NaN
ALB 1961 NaN
ALB 1962 NaN
ALB 2015 1.12214
...
Thanks.

I think need melt with sort_values:
df = (df.melt(['Country Code'], var_name='Year', value_name='Econometric_Metric')
.sort_values(['Country Code','Year'])
.reset_index(drop=True))
Or set_index with stack:
df = (df.set_index(['Country Code'])
.stack(dropna=False)
.reset_index(name='Econometric_Metric')
.rename(columns={'level_1':'Year'}))
print (df.head(10))
Country Code Year Econometric_Metric
0 ABW 1960 2.61530
1 ABW 1961 2.73439
2 ABW 1962 2.67843
3 ABW 1963 2.92992
4 ABW 1964 2.96325
5 ABW 1965 3.06054
6 ABW 1966 NaN
7 ABW 1967 NaN
8 ABW 1968 NaN
9 ABW 2015 4.34976

Related

Python pandas Dataframe column to rows manipulation [duplicate]

This question already has answers here:
Pandas Melt Function
(2 answers)
Closed 1 year ago.
I'm trying to transpose a few columns while keeping the other columns. I'm having a hard time with pivot codes or transpose codes as it doesn't really give me the output I need.
Can anyone help?
I have this data frame:
EmpID
Goal
week 1
week 2
week 3
week 4
1
556
54
33
24
54
2
342
32
32
56
43
3
534
43
65
64
21
4
244
45
87
5
22
My expected dataframe output is:
EmpID
Goal
Weeks
Actual
1
556
week 1
54
1
556
week 2
33
1
556
week 3
24
1
556
week 4
54
and so on until the full employee IDs are listed..
Something like this.
# Python - melt DF
import pandas as pd
d = {'Country Code': [1960, 1961, 1962, 1963, 1964, 1965, 1966],
'ABW': [2.615300, 2.734390, 2.678430, 2.929920, 2.963250, 3.060540, 4.349760],
'AFG': [0.249760, 0.218480, 0.210840, 0.217240, 0.211410, 0.209910, 0.671330],
'ALB': ['NaN', 'NaN', 'NaN', 'NaN', 'NaN', 'NaN', 1.12214]}
df = pd.DataFrame(data=d)
print(df)
df1 = (df.melt(['Country Code'], var_name='Year', value_name='Econometric_Metric')
.sort_values(['Country Code','Year'])
.reset_index(drop=True))
print(df1)
df2 = (df.set_index(['Country Code'])
.stack(dropna=False)
.reset_index(name='Econometric_Metric')
.rename(columns={'level_1':'Year'}))
print(df2)
# BEFORE
ABW AFG ALB Country Code
0 2.61530 0.24976 NaN 1960
1 2.73439 0.21848 NaN 1961
2 2.67843 0.21084 NaN 1962
3 2.92992 0.21724 NaN 1963
4 2.96325 0.21141 NaN 1964
5 3.06054 0.20991 NaN 1965
6 4.34976 0.67133 1.12214 1966
# AFTER
Country Code Year Econometric_Metric
0 1960 ABW 2.6153
1 1960 AFG 0.24976
2 1960 ALB NaN
3 1961 ABW 2.73439
4 1961 AFG 0.21848
5 1961 ALB NaN
6 1962 ABW 2.67843
7 1962 AFG 0.21084
8 1962 ALB NaN
9 1963 ABW 2.92992
10 1963 AFG 0.21724
11 1963 ALB NaN
12 1964 ABW 2.96325
13 1964 AFG 0.21141
14 1964 ALB NaN
15 1965 ABW 3.06054
16 1965 AFG 0.20991
17 1965 ALB NaN
18 1966 ABW 4.34976
19 1966 AFG 0.67133
20 1966 ALB 1.12214
Country Code Year Econometric_Metric
0 1960 ABW 2.6153
1 1960 AFG 0.24976
2 1960 ALB NaN
3 1961 ABW 2.73439
4 1961 AFG 0.21848
5 1961 ALB NaN
6 1962 ABW 2.67843
7 1962 AFG 0.21084
8 1962 ALB NaN
9 1963 ABW 2.92992
10 1963 AFG 0.21724
11 1963 ALB NaN
12 1964 ABW 2.96325
13 1964 AFG 0.21141
14 1964 ALB NaN
15 1965 ABW 3.06054
16 1965 AFG 0.20991
17 1965 ALB NaN
18 1966 ABW 4.34976
19 1966 AFG 0.67133
20 1966 ALB 1.12214
Also, take a look at the link below, for more info.
https://www.dataindependent.com/pandas/pandas-melt/

How to delete rows for column having Non-NaN values

Input Dataframe(df)
Country Region Date Value.....
ABW NaN 01-01-2020 123
ABW NaN 02-01-2020 1234
ABW NaN 03-01-2020 3242
USA NaN 04-01-2020 4354
USA NaN 05-01-2020 43543
USA NaN 06-01-2020 34534
USA NaN 07-01-2020 435
USA WA 08-01-2020 43345
USA WA 09-01-2020 345
USA WV 10-01-2020 345
.
.
.
.
Expected Output(df1)
Country Region Date Value.....
ABW NaN 01-01-2020 123
ABW NaN 02-01-2020 1234
ABW NaN 03-01-2020 3242
USA NaN 04-01-2020 4354
USA NaN 05-01-2020 43543
USA NaN 06-01-2020 34534
USA NaN 07-01-2020 435
.
.
.
.
So from the above dataframe you can see that the column 'Region' has NaN as well as non-null values, I'd like to remove the entire row where column 'Region' has non-NaN values.
Also, AFTER performing the above operation, if I wanted to entirely remove the Region column, how to do that in the fastest possible way(10k+ columns)?? Experts, please help!
FINAL Expected Output
Country Date Value.....
ABW 01-01-2020 123
ABW 02-01-2020 1234
ABW 03-01-2020 3242
USA 04-01-2020 4354
USA 05-01-2020 43543
USA 06-01-2020 34534
USA 07-01-2020 435
Here's the code I tried
df1=df1.isnull(df1['Region'])
Error
df1=df.isnull(df['Region'])
TypeError: isnull() takes 1 positional argument but 2 were given
Using #BEN_YO's suggestion, this is what I did, works fine
filtered_df = df1[df1['Region'].isnull()]

Set "Year" column to individual columns to create a panel

I am trying to reshape the following dataframe such that it is in panel data form by moving the "Year" column such that each year is an individual column.
Out[34]:
Award Year 0
State
Alabama 2003 89
Alabama 2004 92
Alabama 2005 108
Alabama 2006 81
Alabama 2007 71
... ...
Wyoming 2011 4
Wyoming 2012 2
Wyoming 2013 1
Wyoming 2014 4
Wyoming 2015 3
[648 rows x 2 columns]
I want the years to each be individual columns, this is an example,
Out[48]:
State 2003 2004 2005 2006
0 NewYork 10 10 10 10
1 Alabama 15 15 15 15
2 Washington 20 20 20 20
I have read up on stack/unstack but I don't think I want a multilevel index as a result. I have been looking through the documentation at to_frame etc. but I can't see what I am looking for.
If anyone can help that would be great!
Use set_index with append=True then select the column 0 and use unstack to reshape:
df = df.set_index('Award Year', append=True)['0'].unstack()
Result:
Award Year 2003 2004 2005 2006 2007 2011 2012 2013 2014 2015
State
Alabama 89.0 92.0 108.0 81.0 71.0 NaN NaN NaN NaN NaN
Wyoming NaN NaN NaN NaN NaN 4.0 2.0 1.0 4.0 3.0
Pivot Table can help.
df2 = pd.pivot_table(df,values='0', columns='AwardYear', index=['State'])
df2
Result:
AwardYear 2003 2004 2005 2006 2007 2011 2012 2013 2014 2015
State
Alabama 89.0 92.0 108.0 81.0 71.0 NaN NaN NaN NaN NaN
Wyoming NaN NaN NaN NaN NaN 4.0 2.0 1.0 4.0 3.0

Transposing Data in Python

I have data from the World Bank that look like this:
Country Name Country Code 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Aruba ABW 80326 83195 85447 87276 89004 90858 92894 94995 97015 98742 100031 100830 101218 101342 101416 101597 101936 102393 102921 103441 103889
It's population data from 250 some countries and I've just shown the first one for the sake of example. How would I be able to transpose this so that each country and year are on a single row like this?
Country Name Country Code Year Population
Aruba ABW 1995 80326
Aruba ABW 1996 83195
Aruba ABW 1997 85447
Aruba ABW 1998 87276
And so on and so forth
You could use pd.melt.
pd.melt(df, id_vars=['Country Name', 'Country Code'],
var_name='Year', value_name='Population')
Or alternatively, could add the Country Name and Country Code to the index, stack, then reset the index
df = df.set_index(['Country Name', 'Country Code']).stack().reset_index()
but then you'll have to set the column names post-process. pd.melt is probably nicer for this, and is most likely faster as well.
Demo
>>> pd.melt(df, id_vars=['Country Name', 'Country Code'],
var_name='Year', value_name='Population')
Country Name Country Code Year Population
0 Aruba ABW 1995 80326
1 Aruba ABW 1996 83195
2 Aruba ABW 1997 85447
3 Aruba ABW 1998 87276
4 Aruba ABW 1999 89004
5 Aruba ABW 2000 90858
6 Aruba ABW 2001 92894
7 Aruba ABW 2002 94995
8 Aruba ABW 2003 97015
9 Aruba ABW 2004 98742
10 Aruba ABW 2005 100031
11 Aruba ABW 2006 100830
12 Aruba ABW 2007 101218
13 Aruba ABW 2008 101342
14 Aruba ABW 2009 101416
15 Aruba ABW 2010 101597
16 Aruba ABW 2011 101936
17 Aruba ABW 2012 102393
18 Aruba ABW 2013 102921
19 Aruba ABW 2014 103441
20 Aruba ABW 2015 103889

Pandas merge 2 databases based on 2 keys

I am trying to merge 2 pandas df's:
ISO3 Year Calories
AFG 1960 2300
AFG 1961 2323
...
USA 2005 2800
USA 2006 2828
and
ISO3 Year GDP
AFG 1980 3600
AFG 1981 3636
...
USA 2049 10000
USA 2050 10100
I have tried pd.merge(df1,df2,on=['ISO3','Year'],how=outer) and many others, but for some reason it does not work, any help?
pd.merge(df1, df2, on=['ISO3', 'Year'], how='outer') should work just fine. Can you modify the example, or post a concrete example of df1, df2 which is not yielding the correct result?
In [58]: df1 = pd.read_table('data', sep='\s+')
In [59]: df1
Out[59]:
ISO3 Year Calories
0 AFG 1960 2300
1 AFG 1961 2323
2 USA 2005 2800
3 USA 2006 2828
In [60]: df2 = pd.read_table('data2', sep='\s+')
In [61]: df2
Out[61]:
ISO3 Year GDP
0 AFG 1980 3600
1 AFG 1981 3636
2 USA 2049 10000
3 USA 2050 10100
In [62]: pd.merge(df1, df2, on=['ISO3', 'Year'], how='outer')
Out[62]:
ISO3 Year Calories GDP
0 AFG 1960 2300 NaN
1 AFG 1961 2323 NaN
2 USA 2005 2800 NaN
3 USA 2006 2828 NaN
4 AFG 1980 NaN 3600
5 AFG 1981 NaN 3636
6 USA 2049 NaN 10000
7 USA 2050 NaN 10100

Categories