Suppress Scientific Notation in Numpy When Creating Array From Nested List

Question

I have a nested Python list that looks like the following   my list     3 74  5162  13683628846 64  12783387559 86  1 81     9 55  116  189688622 37  260332262 0  1 97     2 2  768  6004865 13  5759960 98  1 21     3 74  4062  3263822121 39  3066869087 9  1 93     1 91  474  44555062 72  44555062 72  0 41     5 8  5006  8254968918 1  7446788272 74  3 25     4 5  7887  30078971595 46  27814989471 31  2 18     7 03  116  66252511 46  81109291 0  1 56     6 52  116  47674230 76  57686991 0  1 43     1 85  623  3002631 96  2899484 08  0 64     13 76  1227  1737874137 5  1446511574 32  4 32     13 76  1227  1737874137 5  1446511574 32  4 32     I then import Numpy  and set print options to  suppress True   When I create an array   my array   numpy array my list    I can t for the life of me suppress scientific notation       3 74000000e 00   5 16200000e 03   1 36836288e 10   1 27833876e 10     1 81000000e 00      9 55000000e 00   1 16000000e 02   1 89688622e 08   2 60332262e 08     1 97000000e 00      2 20000000e 00   7 68000000e 02   6 00486513e 06   5 75996098e 06     1 21000000e 00      3 74000000e 00   4 06200000e 03   3 26382212e 09   3 06686909e 09     1 93000000e 00      1 91000000e 00   4 74000000e 02   4 45550627e 07   4 45550627e 07     4 10000000e-01      5 80000000e 00   5 00600000e 03   8 25496892e 09   7 44678827e 09     3 25000000e 00      4 50000000e 00   7 88700000e 03   3 00789716e 10   2 78149895e 10     2 18000000e 00      7 03000000e 00   1 16000000e 02   6 62525115e 07   8 11092910e 07     1 56000000e 00      6 52000000e 00   1 16000000e 02   4 76742308e 07   5 76869910e 07     1 43000000e 00      1 85000000e 00   6 23000000e 02   3 00263196e 06   2 89948408e 06     6 40000000e-01      1 37600000e 01   1 22700000e 03   1 73787414e 09   1 44651157e 09     4 32000000e 00      1 37600000e 01   1 22700000e 03   1 73787414e 09   1 44651157e 09     4 32000000e 00     If I create a simple numpy array directly   new array   numpy array  1 5  4 65  7 845     I have no problem and it prints as follows     1 5    4 65   7 845    Does anyone know what my problem is

User · Accepted Answer

I guess what you need is np set printoptions suppress True   for details see here  http   pythonquirks blogspot fr 2009 10 controlling-printing-in-numpy html  For SciPy org numpy documentation  which includes all function parameters  suppress isn t detailed in the above link   see here  https   docs scipy org doc numpy reference generated numpy set printoptions html

User · Answer

for 1D and 2D arrays you can use np savetxt to print using a specific format string    gt  gt  gt  import sys  gt  gt  gt  x   numpy arange 20  reshape  4 5    gt  gt  gt  numpy savetxt sys stdout  x    5 2f    0 00  1 00  2 00  3 00  4 00  5 00  6 00  7 00  8 00  9 00 10 00 11 00 12 00 13 00 14 00 15 00 16 00 17 00 18 00 19 00   Your options with numpy set printoptions or numpy array2string in v1 3 are pretty clunky and limited  for example no way to suppress scientific notation for large numbers   It looks like this will change with future versions  with numpy set printoptions formatter     and numpy array2string style

User · Answer

You could write a function that converts a scientific notation to regular  something like  def sc2std x       s   str x      if  e  in s          num ex   s split  e           if  -  in num              negprefix    -          else              negprefix              num   num replace  -              if     in num              dotlocation   num index              else              dotlocation   len num          newdotlocation   dotlocation   int ex          num   num replace                 if  newdotlocation  lt  1               return negprefix  0    0   -newdotlocation  num         if  newdotlocation  gt  len num                return negprefix  num    0   newdotlocation - len num     0          return negprefix   num  newdotlocation          num newdotlocation       else          return s

User · Answer

Python Force-suppress all exponential notation when printing numpy ndarrays  wrangle text justification  rounding and print options   What follows is an explanation for what is going on  scroll to bottom for code demos   Passing parameter suppress True to function set printoptions works only for numbers that fit in the default 8 character space allotted to it  like this   import numpy as np np set printoptions suppress True   prevent numpy exponential                                      notation on print  default False               tiny     med  large a   np array  1 01e-5  22  1 2345678e7     notice how index 2 is 8                                             digits wide  print a      prints   0 0000101   22      12345678      However if you pass in a number greater than 8 characters wide  exponential notation is imposed again  like this   np set printoptions suppress True   a   np array  1 01e-5  22  1 2345678e10       notice how index 2 is 10                                               digits wide  too wide    exponential notation where we ve told it not to  print a      prints  1 01000000e-005   2 20000000e 001   1 23456780e 10    numpy has a choice between chopping your number in half thus misrepresenting it  or forcing exponential notation  it chooses the latter   Here comes set printoptions formatter      to the rescue to specify options for printing and rounding   Tell set printoptions to just print bare a bare float   np set printoptions suppress True     formatter   float kind     f   format    a   np array  1 01e-5  22  1 2345678e30     notice how index 2 is 30                                             digits wide      Ok good  no exponential notation in the large numbers  print a    prints  0 000010 22 000000 1234567799999999979944197226496 000000     We ve force-suppressed the exponential notation  but it is not rounded or justified  so specify extra formatting options   np set printoptions suppress True     formatter   float kind     0 2f   format     float  2 units                                                  precision right  0 on left  a   np array  1 01e-5  22  1 2345678e30      notice how index 2 is 30                                              digits wide  print a    prints  0 00 22 00 1234567799999999979944197226496 00    The drawback for force-suppressing all exponential notion in ndarrays is that if your ndarray gets a huge float value near infinity in it  and you print it  you re going to get blasted in the face with a page full of numbers     Full example Demo 1   from pprint import pprint import numpy as np  chaotic python list of lists with very different numeric magnitudes my list     3 74  5162  13683628846 64  12783387559 86  1 81               9 55  116  189688622 37  260332262 0  1 97               2 2  768  6004865 13  5759960 98  1 21               3 74  4062  3263822121 39  3066869087 9  1 93               1 91  474  44555062 72  44555062 72  0 41               5 8  5006  8254968918 1  7446788272 74  3 25               4 5  7887  30078971595 46  27814989471 31  2 18               7 03  116  66252511 46  81109291 0  1 56               6 52  116  47674230 76  57686991 0  1 43               1 85  623  3002631 96  2899484 08  0 64               13 76  1227  1737874137 5  1446511574 32  4 32               13 76  1227  1737874137 5  1446511574 32  4 32     convert python list of lists to numpy ndarray called my array my array   np array my list    This is a little recursive helper function converts all nested   ndarrays to python list of lists so that pretty printer knows what to do  def arrayToList arr       if type arr     type np array            If the passed type is an ndarray then convert it to a list and          recursively convert all nested types         return arrayToList arr tolist        else           if item isn t an ndarray leave it as is          return arr   suppress exponential notation  define an appropriate float formatter  specify stdout line width and let pretty print do the work np set printoptions suppress True     formatter   float kind     16 3f   format   linewidth 130  pprint arrayToList my array     Prints    array              3 740          5162 000   13683628846 640   12783387559 860             1 810                      9 550           116 000     189688622 370     260332262 000             1 970                      2 200           768 000       6004865 130       5759960 980             1 210                      3 740          4062 000    3263822121 390    3066869087 900             1 930                      1 910           474 000      44555062 720      44555062 720             0 410                      5 800          5006 000    8254968918 100    7446788272 740             3 250                      4 500          7887 000   30078971595 460   27814989471 310             2 180                      7 030           116 000      66252511 460      81109291 000             1 560                      6 520           116 000      47674230 760      57686991 000             1 430                      1 850           623 000       3002631 960       2899484 080             0 640                     13 760          1227 000    1737874137 500    1446511574 320             4 320                     13 760          1227 000    1737874137 500    1446511574 320             4 320      Full example Demo 2   import numpy as np    chaotic python list of lists with very different numeric magnitudes                very tiny      medium size            large sized              numbers        numbers                numbers  my list     0 000000000074  5162  13683628846 64  1 01e10  1 81                1 000000000055   116  189688622 37  260332262 0  1 97                0 010000000022   768  6004865 13    -99e13  1 21                1 000000000074  4062  3263822121 39  3066869087 9  1 93                2 91             474  44555062 72  44555062 72  0 41                5               5006  8254968918 1  7446788272 74  3 25                0 01            7887  30078971595 46  27814989471 31  2 18                7 03             116  66252511 46  81109291 0  1 56                6 52             116  47674230 76  57686991 0  1 43                1 85             623  3002631 96  2899484 08  0 64                13 76           1227  1737874137 5  1446511574 32  4 32                13 76           1337  1737874137 5  1446511574 32  4 32    import sys   convert python list of lists to numpy ndarray called my array  my array   np array my list    following two lines do the same thing  showing that np savetxt can   correctly handle python lists of lists and numpy 2D ndarrays   np savetxt sys stdout  my list    19 2f    np savetxt sys stdout  my array    19 2f      Prints     0 00             5162 00      13683628846 64      10100000000 00              1 81  1 00              116 00        189688622 37        260332262 00              1 97  0 01              768 00          6004865 13 -990000000000000 00              1 21  1 00             4062 00       3263822121 39       3066869087 90              1 93  2 91              474 00         44555062 72         44555062 72              0 41  5 00             5006 00       8254968918 10       7446788272 74              3 25  0 01             7887 00      30078971595 46      27814989471 31              2 18  7 03              116 00         66252511 46         81109291 00              1 56  6 52              116 00         47674230 76         57686991 00              1 43  1 85              623 00          3002631 96          2899484 08              0 64 13 76             1227 00       1737874137 50       1446511574 32              4 32 13 76             1337 00       1737874137 50       1446511574 32              4 32  0 00             5162 00      13683628846 64      10100000000 00              1 81  1 00              116 00        189688622 37        260332262 00              1 97  0 01              768 00          6004865 13 -990000000000000 00              1 21  1 00             4062 00       3263822121 39       3066869087 90              1 93  2 91              474 00         44555062 72         44555062 72              0 41  5 00             5006 00       8254968918 10       7446788272 74              3 25  0 01             7887 00      30078971595 46      27814989471 31              2 18  7 03              116 00         66252511 46         81109291 00              1 56  6 52              116 00         47674230 76         57686991 00              1 43  1 85              623 00          3002631 96          2899484 08              0 64 13 76             1227 00       1737874137 50       1446511574 32              4 32 13 76             1337 00       1737874137 50       1446511574 32              4 32   Notice that rounding is consistent at 2 units precision  and exponential notation is suppressed in both the very large e x and very small e-x ranges

[python] Suppress Scientific Notation in Numpy When Creating Array From Nested List

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