csv - Using Unstack in Python -


i trying unstack column in python isn't quite doing expecting. table (called df) looks similar this:

station_id   year     day1   day2   210018       1916      4        7               1917      3        9   256700       1916     nan       8               1917      6        9

i want unstack year days year per stationn in 1 row. 2 days 1916 start first followed 2 days 1917 station 210018 , 256700.

an example this:

station_id            1916       1917 210018                4   7      3  9  256700                nan  8     6   9

i trying use code: 

df2=df.unstack(level='year') df2.columns=df2.columns.swaplevel(0,1) df2=df2.sort(axis=1)

i error says attributeerror: 'series' object has no attribute 'columns'.

any appreciated.

you need make year index before call unstack:

try:     # python2     cstringio import stringio  except importerror:     # python3     io import stringio  import pandas pd   text = '''\ station_id   year     day1   day2   210018       1916      4        7  210018       1917      3        9   256700       1916     nan       8  256700       1917      6        9'''  df = pd.read_table(stringio(text), sep='\s+') df = df.set_index(['station_id', 'year']) df2 = df.unstack(level='year') df2.columns = df2.columns.swaplevel(0,1) df2 = df2.sort(axis=1) print(df2)

yields

year       1916      1917                 day1 day2 day1 day2 station_id                     210018        4    7    3    9 256700      nan    8    6    9

whereas, if year column, , not index, then

df = pd.read_table(stringio(text), sep='\s+') df = df.set_index(['station_id'])    df2 = df.unstack(level='year') df2.columns = df2.columns.swaplevel(0,1) df2 = df2.sort(axis=1)

leads attributeerror: 'series' object has no attribute 'columns'.

the level='year' ignored in df.unstack(level='year') when df not have index level named year (or even, say, blah):

in [102]: df out[102]:              year  day1  day2 station_id                   210018      1916     4     7 210018      1917     3     9 256700      1916   nan     8 256700      1917     6     9  in [103]: df.unstack(level='blah') out[103]:        station_id year  210018        1916       210018        1917       256700        1916       256700        1917 day1  210018           4       210018           3       256700         nan       256700           6 day2  210018           7       210018           9       256700           8       256700           9 dtype: float64

this source of surprising error.


Comments

Post a Comment

Popular posts from this blog

cakephp - simple blog with croogo -

i not problem, made simple blog in croogo, problem is not adding or modifying or delete, because arabic language ?? function add in controller `public function admin_add() { $this->set('title_for_layout', __('add part')); if (!empty($this->request->data)) { $this->part->create(); if ($this->part->save($this->request->data)) { $this->session->setflash(__('the part has been saved'), 'default', array('class' => 'success')); $this->redirect(array('action' => 'index'));//, $this->part->id)); } else { $this->session->setflash(__('the part not saved. please, try again.'), 'default', array('class' => 'error')); } } }` => model `class part extends appmodel { public $name = 'part'; var $belongst...
Read more

How to group boxplot outliers in gnuplot -

i have large set of data points. try plot them boxplot, of outliers exact same value , represented on line beside each other. found how set horizontal distance between outliers in gnuplot boxplot , doesn't much, apparently not possible. is possible group outliers together, print 1 point , print number in brackets beside indicate how many points there are? think make more readable in graph. for information, have 3 boxplots 1 x value , times 6 in 1 graph. using gnuplot 5 , played around pointsize, doesn't reduce distance anymore. hope can help! edit: set terminal pdf set output 'dat.pdf' file0 = 'dat1.dat' file1 = 'dat2.dat' file2 = 'dat3.dat' set pointsize 0.2 set notitle set xlabel 'x' set ylabel 'y' header = system('head -1 '.file0); n = words(header) set xtics ('' 1) set [i=1:n] xtics add (word(header, i) i) set style data boxplot plot file0 using (1-0.25):1:(0.2) boxplot lw 2 lc rgb '#8b0000...
Read more

bash - Performing variable substitution in a string -

i have string contains use of variable, , i'd substitute variable's value string. right best have is #!/bin/bash foo='$name; echo bar' name="the name" expanded="$(eval echo "$foo")" echo "$expanded" which has obvious defects: prints the name bar while i'd print the name; echo bar instead of eval can bash's regex matching bash's string replacement: foo='$name; echo bar' name="the name" [[ "$foo" =~ \$([[:alnum:]]+) ]] && s="${!bash_rematch[1]}" && expanded="${foo/\$${bash_rematch[1]}/$s}" echo "$expanded" name; echo bar
Read more