Prevent IPython from displaying long lists one element per line - python

In Jupyter notebooks, or in IPython, long lists are displayed one element per line. How do I display them on a single line? I don't mind if the line wraps.
In the following example, I'd like the 3rd list to be shown as a "row", not as a "column".
In [1]: [list(range(n)) for n in range(10,40,10)]
Out[1]:
[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19],
[0,
1,
2,
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19,
20,
21,
22,
23,
24,
25,
26,
27,
28,
29]]
The output I am looking for is the following or similar:
[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19],
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]]
My goal is to make the output easier to read for humans.


I would simply use
A = [list(range(n)) for n in range(10,40,10)]
for i in A:
print(i)

Related

matplotlib quiver() displaying double arrows

The code below is producing double arrows. This is most noticeable in the center and along the bottom row.
Am I missing something or is this a bug of some sort? The Googlebox has yielded nothing helpful.
X = [[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22]]
Y = [[ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1],
[ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1],
[ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2],
[ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3],
[ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4],
[ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
5, 5, 5, 5, 5, 5, 5, 5],
[ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
6, 6, 6, 6, 6, 6, 6, 6],
[ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7],
[ 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8],
[ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
9, 9, 9, 9, 9, 9, 9, 9],
[10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
10, 10, 10, 10, 10, 10, 10, 10],
[11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
11, 11, 11, 11, 11, 11, 11, 11],
[12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
12, 12, 12, 12, 12, 12, 12, 12],
[12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
12, 12, 12, 12, 12, 12, 12, 12],
[13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
13, 13, 13, 13, 13, 13, 13, 13],
[14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14],
[15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15],
[16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
16, 16, 16, 16, 16, 16, 16, 16],
[17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17,
17, 17, 17, 17, 17, 17, 17, 17],
[18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18,
18, 18, 18, 18, 18, 18, 18, 18],
[19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19,
19, 19, 19, 19, 19, 19, 19, 19],
[20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
20, 20, 20, 20, 20, 20, 20, 20],
[21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
21, 21, 21, 21, 21, 21, 21, 21],
[22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22],
[23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23]]
U = [[ 5.91106782e-01, 6.22366562e-01, 6.49723913e-01,
6.58423221e-01, 6.34788082e-01, 5.64001424e-01,
4.29552877e-01, 2.26181450e-01, -1.45749370e-02,
-2.33836090e-01, -3.97062982e-01, -5.07288787e-01,
-5.80344621e-01, -6.28652118e-01, -6.56798746e-01,
-6.59563028e-01, -6.18178096e-01, -5.00722193e-01,
-2.93582966e-01, -5.16521582e-02, 1.45799368e-01,
2.69658133e-01, 3.26500153e-01, 3.26768709e-01],
[ 5.77152607e-01, 5.82746773e-01, 5.76183972e-01,
5.43266956e-01, 4.66312191e-01, 3.24661378e-01,
1.07385088e-01, -1.54908642e-01, -3.91341641e-01,
-5.56849441e-01, -6.55288824e-01, -7.07393105e-01,
-7.30393353e-01, -7.34785105e-01, -7.24202206e-01,
-6.92703347e-01, -6.16664334e-01, -4.51489078e-01,
-1.96144234e-01, 3.89095593e-02, 1.80222779e-01,
2.38107484e-01, 2.33390450e-01, 1.75753839e-01],
[ 5.55201554e-01, 5.36916267e-01, 4.95331092e-01,
4.14297782e-01, 2.72441471e-01, 5.30267270e-02,
-2.23958353e-01, -4.85686407e-01, -6.72063827e-01,
-7.80930667e-01, -8.34052999e-01, -8.49154520e-01,
-8.36753045e-01, -8.02912499e-01, -7.48984464e-01,
-6.66861836e-01, -5.28032125e-01, -2.83307017e-01,
2.22999217e-02, 2.17035214e-01, 2.78107345e-01,
2.57213982e-01, 1.80414526e-01, 5.58040480e-02],
[ 5.30514869e-01, 4.88045325e-01, 4.08507605e-01,
2.73305715e-01, 6.32261747e-02, -2.15499555e-01,
-5.00468423e-01, -7.16424820e-01, -8.46362641e-01,
-9.11763344e-01, -9.32463829e-01, -9.17913774e-01,
-8.71699781e-01, -7.94959450e-01, -6.84618047e-01,
-5.27977847e-01, -3.00601184e-01, 3.24725025e-03,
2.84572480e-01, 4.15678719e-01, 4.08817699e-01,
3.17903989e-01, 1.68926905e-01, -2.47734503e-02],
[ 5.02548139e-01, 4.33179379e-01, 3.10308116e-01,
1.15832201e-01, -1.53873192e-01, -4.53740654e-01,
-7.02597717e-01, -8.60992569e-01, -9.43881451e-01,
-9.75369646e-01, -9.68057700e-01, -9.24950942e-01,
-8.45413757e-01, -7.27664488e-01, -5.66705523e-01,
-3.53336189e-01, -8.54415234e-02, 2.02537484e-01,
4.30399404e-01, 5.35069052e-01, 5.14397103e-01,
3.91608994e-01, 1.87450108e-01, -6.90256334e-02],
[ 4.65201575e-01, 3.63695264e-01, 1.90407737e-01,
-6.27986111e-02, -3.66107539e-01, -6.43527995e-01,
-8.36008710e-01, -9.43058071e-01, -9.89396085e-01,
-9.93329532e-01, -9.61559805e-01, -8.93929627e-01,
-7.88224158e-01, -6.41454775e-01, -4.49066265e-01,
-2.09439702e-01, 6.10838713e-02, 3.17493844e-01,
5.06540308e-01, 5.97919655e-01, 5.83094325e-01,
4.57218933e-01, 2.21129548e-01, -8.56001665e-02],
[ 4.07605489e-01, 2.67483222e-01, 4.05687053e-02,
-2.54052862e-01, -5.49121397e-01, -7.74824152e-01,
-9.12683654e-01, -9.80602627e-01, -9.99708951e-01,
-9.81982007e-01, -9.30930539e-01, -8.45440583e-01,
-7.22549396e-01, -5.57873670e-01, -3.47081454e-01,
-9.50528305e-02, 1.70316784e-01, 4.02869279e-01,
5.66564552e-01, 6.47406192e-01, 6.37165072e-01,
5.16241932e-01, 2.63738110e-01, -8.10456144e-02],
[ 3.16982526e-01, 1.36224084e-01, -1.31317283e-01,
-4.28869103e-01, -6.80165940e-01, -8.50494619e-01,
-9.46930042e-01, -9.87780174e-01, -9.87413002e-01,
-9.53497923e-01, -8.88237499e-01, -7.90275139e-01,
-6.55616984e-01, -4.77864944e-01, -2.52458286e-01,
9.81222811e-03, 2.71633461e-01, 4.87237886e-01,
6.32706314e-01, 7.04459838e-01, 6.96319353e-01,
5.81475147e-01, 3.21122831e-01, -5.36729232e-02],
[ 1.89851174e-01, -1.85511352e-02, -2.92612142e-01,
-5.56206782e-01, -7.55569048e-01, -8.83561174e-01,
-9.52641527e-01, -9.75602026e-01, -9.61454612e-01,
-9.15325308e-01, -8.38796591e-01, -7.30116952e-01,
-5.83859882e-01, -3.91508312e-01, -1.49024508e-01,
1.25224816e-01, 3.84250312e-01, 5.84434393e-01,
7.13492616e-01, 7.76382012e-01, 7.69585148e-01,
6.63495229e-01, 4.05530281e-01, 8.00655892e-03],
[ 4.93393011e-02, -1.59077638e-01, -4.07446556e-01,
-6.27159359e-01, -7.86840781e-01, -8.87988595e-01,
-9.40149757e-01, -9.51231448e-01, -9.26802697e-01,
-8.70250066e-01, -7.82391229e-01, -6.60618012e-01,
-4.97916636e-01, -2.84557428e-01, -2.01313492e-02,
2.65144709e-01, 5.15478531e-01, 6.95092413e-01,
8.05054050e-01, 8.57357453e-01, 8.51220724e-01,
7.58939184e-01, 5.22126402e-01, 1.20841224e-01],
[-6.08161695e-02, -2.48600589e-01, -4.63433277e-01,
-6.50364713e-01, -7.86735731e-01, -8.73048406e-01,
-9.15192518e-01, -9.18037801e-01, -8.84901395e-01,
-8.17468539e-01, -7.15217876e-01, -5.74265632e-01,
-3.86590763e-01, -1.44298331e-01, 1.42640838e-01,
4.27841719e-01, 6.54596037e-01, 8.04151106e-01,
8.90457558e-01, 9.29136623e-01, 9.21288722e-01,
8.45538031e-01, 6.51467861e-01, 2.89354206e-01],
[-1.11855856e-01, -2.76262916e-01, -4.66494984e-01,
-6.36195917e-01, -7.62707033e-01, -8.42791922e-01,
-8.79618811e-01, -8.76344309e-01, -8.34510258e-01,
-7.53704299e-01, -6.31437753e-01, -4.62760383e-01,
-2.41283252e-01, 3.19831190e-02, 3.28392442e-01,
5.90402526e-01, 7.76991386e-01, 8.90488023e-01,
9.51679598e-01, 9.75365138e-01, 9.63233139e-01,
9.01562554e-01, 7.57051594e-01, 4.78793525e-01],
[-1.02763752e-01, -2.49208456e-01, -4.25698141e-01,
-5.90445663e-01, -7.17037110e-01, -7.97411218e-01,
-8.32440059e-01, -8.24121526e-01, -7.72259450e-01,
-6.73888301e-01, -5.24476588e-01, -3.20200623e-01,
-6.29603397e-02, 2.27897175e-01, 5.06403936e-01,
7.23466314e-01, 8.64328407e-01, 9.44675955e-01,
9.84485357e-01, 9.95247332e-01, 9.78583745e-01,
9.26839981e-01, 8.22017325e-01, 6.32198023e-01],
[-4.76297792e-02, -1.80235400e-01, -3.48835361e-01,
-5.15498990e-01, -6.48860867e-01, -7.34607790e-01,
-7.70573611e-01, -7.57371172e-01, -6.92888223e-01,
-5.71674412e-01, -3.88941513e-01, -1.47948226e-01,
1.31928638e-01, 4.12166625e-01, 6.47847253e-01,
8.14343231e-01, 9.16397002e-01, 9.71963635e-01,
9.96490008e-01, 9.98129614e-01, 9.78410399e-01,
9.33624383e-01, 8.55392368e-01, 7.29066548e-01],
[ 3.44453327e-02, -8.45500183e-02, -2.44567678e-01,
-4.13390951e-01, -5.55986626e-01, -6.50278759e-01,
-6.88905719e-01, -6.69887784e-01, -5.89049719e-01,
-4.40034407e-01, -2.23153205e-01, 4.24368019e-02,
3.17706147e-01, 5.60575371e-01, 7.45372080e-01,
8.69074149e-01, 9.43218293e-01, 9.82237250e-01,
9.96859104e-01, 9.92775230e-01, 9.71548772e-01,
9.31926675e-01, 8.70952635e-01, 7.84147337e-01],
[ 1.24531829e-01, 2.14951720e-02, -1.24142269e-01,
-2.88285785e-01, -4.36332137e-01, -5.38600278e-01,
-5.79503157e-01, -5.52137571e-01, -4.50556205e-01,
-2.72020914e-01, -3.08257107e-02, 2.33881288e-01,
4.76396240e-01, 6.69624907e-01, 8.08474102e-01,
9.00042790e-01, 9.55065954e-01, 9.83283570e-01,
9.91629328e-01, 9.84084754e-01, 9.62320925e-01,
9.26691302e-01, 8.77415997e-01, 8.15482847e-01],
[ 2.08997618e-01, 1.24559020e-01, 8.48684407e-04,
-1.46598137e-01, -2.88661918e-01, -3.91618296e-01,
-4.29961569e-01, -3.89309376e-01, -2.63943288e-01,
-6.30136416e-02, 1.78668276e-01, 4.12249396e-01,
6.04758495e-01, 7.48714864e-01, 8.50152685e-01,
9.17783980e-01, 9.59112226e-01, 9.79804775e-01,
9.83901943e-01, 9.74114572e-01, 9.52212374e-01,
9.19706766e-01, 8.78912089e-01, 8.33903997e-01],
[ 2.82249691e-01, 2.18162184e-01, 1.22747194e-01,
5.37550368e-03, -1.12692673e-01, -1.99604825e-01,
-2.22963823e-01, -1.62177004e-01, -1.79584651e-02,
1.81399471e-01, 3.89284568e-01, 5.68595908e-01,
7.06857534e-01, 8.07907267e-01, 8.79716132e-01,
9.28814854e-01, 9.59433518e-01, 9.74181247e-01,
9.74926863e-01, 9.63345918e-01, 9.41247109e-01,
9.11068122e-01, 8.76727946e-01, 8.44239721e-01],
[ 3.46009504e-01, 3.03334542e-01, 2.40609727e-01,
1.64792336e-01, 9.10650256e-02, 4.46918062e-02,
5.47680721e-02, 1.36260477e-01, 2.74393229e-01,
4.32734135e-01, 5.78349795e-01, 6.96327399e-01,
7.86097123e-01, 8.52735284e-01, 9.01501863e-01,
9.35893510e-01, 9.57589073e-01, 9.67107013e-01,
9.64733890e-01, 9.51264330e-01, 9.28488288e-01,
8.99692809e-01, 8.70252069e-01, 8.47561147e-01],
[ 4.06955125e-01, 3.86836289e-01, 3.60008319e-01,
3.33800629e-01, 3.19793639e-01, 3.32294319e-01,
3.80910459e-01, 4.60529276e-01, 5.54085368e-01,
6.45433976e-01, 7.25560042e-01, 7.91585217e-01,
8.44113209e-01, 8.85113897e-01, 9.16480279e-01,
9.39239758e-01, 9.53365969e-01, 9.58045905e-01,
9.52421824e-01, 9.36509635e-01, 9.12084965e-01,
8.83417478e-01, 8.57475919e-01, 8.42768229e-01],
[ 4.75102487e-01, 4.79444876e-01, 4.91103049e-01,
5.17028392e-01, 5.61580652e-01, 6.19364889e-01,
6.75394533e-01, 7.20462603e-01, 7.57762648e-01,
7.92301360e-01, 8.25331968e-01, 8.55937836e-01,
8.83019438e-01, 9.05962858e-01, 9.24460078e-01,
9.38025098e-01, 9.45636106e-01, 9.45638264e-01,
9.36251692e-01, 9.16741704e-01, 8.89028586e-01,
8.58882429e-01, 8.35359426e-01, 8.27878351e-01],
[ 5.62693753e-01, 5.93592734e-01, 6.42845488e-01,
7.09881932e-01, 7.82737342e-01, 8.39735853e-01,
8.68496463e-01, 8.76464004e-01, 8.77560033e-01,
8.80145097e-01, 8.86486243e-01, 8.95793855e-01,
9.06385360e-01, 9.16670844e-01, 9.25375659e-01,
9.31289596e-01, 9.32857010e-01, 9.27783629e-01,
9.13322352e-01, 8.87929386e-01, 8.54220866e-01,
8.20792210e-01, 7.99707058e-01, 8.00713493e-01],
[ 6.75223956e-01, 7.28299137e-01, 7.98132045e-01,
8.70828514e-01, 9.28100696e-01, 9.58357163e-01,
9.63664076e-01, 9.54511170e-01, 9.41109289e-01,
9.29563623e-01, 9.22166117e-01, 9.18823138e-01,
9.18280235e-01, 9.18945445e-01, 9.19301773e-01,
9.17852346e-01, 9.12687865e-01, 9.00755102e-01,
8.77918913e-01, 8.41778780e-01, 7.97438172e-01,
7.59412209e-01, 7.43766496e-01, 7.58426057e-01],
[ 7.48028585e-01, 8.00967465e-01, 8.60639839e-01,
9.17314355e-01, 9.62374525e-01, 9.89077372e-01,
9.96239777e-01, 9.88737117e-01, 9.73767736e-01,
9.57273913e-01, 9.42647501e-01, 9.30980153e-01,
9.21800247e-01, 9.13829662e-01, 9.05516974e-01,
8.95103386e-01, 8.80063037e-01, 8.55819040e-01,
8.15680432e-01, 7.57286053e-01, 6.94667063e-01,
6.54674360e-01, 6.55242773e-01, 6.95951505e-01],
[ 5.88142228e-01, 6.56524283e-01, 7.39388262e-01,
8.26540072e-01, 9.05382649e-01, 9.63084972e-01,
9.93428420e-01, 9.99593348e-01, 9.90003898e-01,
9.72940215e-01, 9.53944608e-01, 9.35599844e-01,
9.18217361e-01, 9.00665492e-01, 8.80954002e-01,
8.56210996e-01, 8.21553193e-01, 7.67628947e-01,
6.82523479e-01, 5.74145986e-01, 4.89341942e-01,
4.69017002e-01, 5.14459717e-01, 6.05048760e-01]]
V = [[-7.64071106e-01, -7.61939824e-01, -7.56999777e-01,
fig, ax = plt.subplots(figsize=(6, 6), dpi=300);
ax.quiver(X, Y, U, V, pivot='middle');
ax.set_aspect('equal');
Output:
I've tried the above. I expect single arrows as usual.
I don't know what additional details to add to get rid of the

Didn't you ask for exactly that, repeating values 1 and 12?
#(...)
X = [[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
[ 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22],
#(...)
Y = [[ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1],
[ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1],
#(...)
U = [[ 5.91106782e-01, 6.22366562e-01, 6.49723913e-01, (...)
[ 5.77152607e-01, 5.82746773e-01, 5.76183972e-01, (...)
You even have a quadruple arrow at coordinate (1,1). Just pair X and Y, and see that X=1 Y=1 occurs 4 times! But values of U in those 4 occurences of X=1 Y=1 are all different. So those 4 arrows that starts for (1,1) are not exactly identical.
So does X=11 Y=1.
X=2 Y=1 occurs twice.
Etc.
You said "especially in the center". No, not really. It occurs on line Y=1, on column X=1, and, indeed on line Y=12 and column X=11 that both pass not far from the center.

"list index out of range" when using random to pick item

I'm learning python and I wrote a program to pick a random office episode to watch and 75% of the time my program works but the other 25%, it gives me the error :
list index out of range.
I've tried messing with the min max values in the line that chooses the episode
import random as r
seasons = [
[1, 2, 3, 4, 5, 5, 6],
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22],
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23],
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14],
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28],
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26],
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26],
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24],
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23]
]
def choose_ep():
global seasons
s = r.randint(1,10) # 1 - 10, not including 10
e = r.randint(min(seasons[s - 1]), max(seasons[s - 1]))
print("Season: " + str(s) + ", Episode: " + str(e))
while True:
choose_ep()
if input() == "exit":
break
I want it to give me a random episode from a random season. I don't want it to give me an episode that doesn't exist like "season 1, episode 14"

https://docs.python.org/3/library/random.html#random.randint
random.randint(a, b)
Return a random integer N such that a <= N <= b. Alias for randrange(a, b+1).
So 10 is in fact included in the values of variable s and hence you get your error.

Alternative solution with no index generation:
import random as r
season_number, episode_list = r.choice(list(enumerate(seasons)))
season_number += 1
episode_number = r.choice(episode_list)
print(season_number, episode_number)

Most computationally efficient way to build a Python list with repeating and iterating numbers like [0, 0, 0, 1, 1, 1, 2, 2, 2 . . . ,etc]

I want to make an array that looks something like
[0, 0, 0, 1, 1 , 1, 2, 2, 2, . . .etc]
or
[4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, . . . etc]
There is something like
segments = [i for i in range(32)]
which will make
[ 1, 2, 3, 4, 5, . . . etc]
There are ways where I can call 3 separate sets of i in range(32) but I am looking to save computation by only calling it once.
What's the most computationally efficient and programatically elegant way of making array like
[0, 0, 0, 1, 1 , 1, 2, 2, 2, . . .etc]

Use itertools.chain on itertools.repeat iterables:
import itertools
result = list(itertools.chain.from_iterable(itertools.repeat(i,3) for i in range(32)))
print(result)
result:
[0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 19, 20, 20, 20, 21, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 24, 25, 25, 25, 26, 26, 26, 27, 27, 27, 28, 28, 28, 29, 29, 29, 30, 30, 30, 31, 31, 31]
This technique avoids the creation of intermediate lists and minimizes the pure python loops (one python loop total, using map could be possible to remove that last one, but that would require a lambda in that case, which adds one more function call).
EDIT: let's bench this answer and Ted's answer
import itertools,time
n=1000000
start_time = time.time()
for _ in range(n):
list(itertools.chain.from_iterable(itertools.repeat(i,3) for i in range(32)))
print("itertools",time.time() - start_time)
start_time = time.time()
for _ in range(n):
[i for i in range(32) for _ in range(3)]
print("flat listcomp",time.time() - start_time)
results:
itertools 10.719785928726196
flat listcomp 13.869723081588745
so using itertools instead of list comprension is around 30% faster (python 3.4, windows)
Notes:
the small number of repeats generates a lot of itertools.repeat calls in the inner loop, so in that case of 3 repeats, it's faster to do what NickA suggests:
list(itertools.chain.from_iterable((i,)*3 for i in range(32)))
(7 seconds vs 10 in the above bench)
And numpy solution is even faster (around 1.5 second), if you can use numpy:
import numpy as np
np.arange(32).repeat(3) # credits: liliscent

Just use nested loops in the list comprehension.
segments = [i for i in range(32) for _ in range(3)]
Output:
[0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 19, 20, 20, 20, 21, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 24, 25, 25, 25, 26, 26, 26, 27, 27, 27, 28, 28, 28, 29, 29, 29, 30, 30, 30, 31, 31, 31]

Use floor division:
def repeated_value_list(repeats, start, stop=None):
if stop is None:
start, stop = 0, start
return [x//repeats for x in range(start*repeats, stop*repeats)]
Example output:
>>> repeated_value_list(3, 5)
[0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4]
>>> repeated_value_list(3, 4, 10)
[4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9]
This is even more efficient if you actually want a numpy array, since broadcasting lets the floor division happen without a comprehension:
import numpy as np
def repeated_value_array(repeats, start, stop=None):
if stop is None:
start, stop = 0, start
return np.arange(start*repeats, stop*repeats) // repeats
Output:
>>> repeated_value_array(3, 5)
array([0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4], dtype=int32)

If we had [(0, 0, 0), (1, 1, 1), …], we'd just have to flatten that:
[elem for sublst in lst for elem in sublst]
How do we get that? Well, if we had three separate sequences [0, 1, 2, …], we could just zip them together:
lst = zip(r1, r2, r3)
And those three sequences are just range(32):
lst = zip(range(32), range(32), range(32))
… or, if you want it to be dynamic rather than exactly 32 and 3:
lst = zip(*(range(count) for _ in range(reps)))
Either way, you can put it together into a one-liner:
[elem for sublst in zip(*(range(count) for _ in range(reps))) for elem in sublst]
And then you can simplify that:
[elem for elem in range(count) for _ in range(reps)]

You can do this using itertools.chain.from_iterable:
>>> list(itertools.chain.from_iterable([[i]*3 for i in range(32)]))
[0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 19, 20, 20, 20, 21, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 24, 25, 25, 25, 26, 26, 26, 27, 27, 27, 28, 28, 28, 29, 29, 29, 30, 30, 30, 31, 31, 31]

Matplotlib color assignment error?

I'm trying to make a colorful scatter plot based on data in an array:
plt.scatter(150, 93, c=y_pred)
Here, y_pred is:
array([ 5, 6, 8, 16, 21, 12, 12, 13, 6, 6, 17, 11, 6, 12, 12, 23, 6,
6, 15, 6, 6, 6, 6, 6, 6, 23, 22, 6, 12, 17, 6, 20, 0, 6,
6, 12, 12, 0, 6, 6, 6, 6, 6, 6, 5, 17, 6, 6, 11, 10, 13,
6, 22, 24, 23, 6, 6, 13, 6, 6, 6, 12, 9, 15, 13, 14, 6, 18,
1, 6, 9, 6, 6, 11, 6, 5, 16, 9, 23, 2, 14, 24, 9, 5, 9,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 1, 6, 19, 6, 23, 3,
20, 10, 4, 8, 9, 6, 6, 9, 22, 23, 6, 6, 11, 6, 6, 6, 22,
24, 14, 4, 7, 12, 6, 19, 6, 12, 3, 22, 6, 11, 6, 21, 23, 4,
6, 6, 6, 4, 10, 22, 15, 6, 6, 18, 6, 14, 4, 5], dtype=int32)
This gives me an error:
ValueError: Invalid RGBA argument: 17
I don't understand why. The same solution works for others. Could you help me understand the error?

You only add one scatter point at x=150 ; y=93 but you try to assign 150 colors for this one value.
plt.scatter(150, 93)
It works if you pass in x and y that have the same shape as c:
plt.scatter(np.random.random(150), np.random.random(150), c=y_pred)

swap elements of list in recursive call python

I want to make simple function swap random element in list.
but it doesn't work in recursive call.
in first recursive call, element swapping work,
but nested recursive call(or nested recursive call in first recursive call) doesn't work.
I don't know why only swap in first recursive call works.
below are result.
Thank you all.
def change(lst):
if len(lst)>4:
a, b = np.random.randint(0, len(lst)), np.random.randint(0, len(lst))
print(lst)
lst[a], lst[b] = lst[b], lst[a]
print(lst)
mid = int(len(lst)/2)
change(lst[:mid])
change(lst[mid:])
k = list(range(0, 20))
change(k)
print(k)
`
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]
[0, 19, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 1]
[0, 19, 2, 3, 4, 5, 6, 7, 8, 9]
[3, 19, 2, 0, 4, 5, 6, 7, 8, 9]
[3, 19, 2, 0, 4]
[3, 0, 2, 19, 4]
[5, 6, 7, 8, 9]
[5, 6, 8, 7, 9]
[10, 11, 12, 13, 14, 15, 16, 17, 18, 1]
[10, 11, 12, 13, 14, 15, 16, 17, 18, 1]
[10, 11, 12, 13, 14]
[10, 14, 12, 13, 11]
[15, 16, 17, 18, 1]
[15, 16, 17, 18, 1]
[0, 19, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 1] <= result.

The problem is that in your recursive calls:
change(lst[:mid])
change(lst[mid:])
you use a slicing operator. The slicing operator constructs a new list, so your changes are made on a new list and are not reflected on the original list (since it is a copy).
What you can do is use indices instead:
def change(lst,frm=0,to=None):
if to is None: # set the default to the end of the list
to = len(lst)
if to-frm > 4:
a, b = np.random.randint(frm,to), np.random.randint(frm,to)
print(lst)
lst[a], lst[b] = lst[b], lst[a]
print(lst)
mid = (frm+to)//2
change(lst,frm,mid)
change(lst,mid,to)
Then we obtain:
>>> k = list(range(0, 20))
>>> change(k)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 2, 3, 4, 12, 6, 7, 8, 9, 10, 11, 5, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 2, 3, 4, 12, 6, 7, 8, 9, 10, 11, 5, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 2, 3, 4, 12, 6, 7, 8, 9, 10, 11, 5, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 2, 3, 4, 12, 6, 7, 8, 9, 10, 11, 5, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 4, 3, 2, 12, 6, 7, 8, 9, 10, 11, 5, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 4, 3, 2, 12, 6, 7, 8, 9, 10, 11, 5, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 4, 3, 2, 7, 6, 12, 8, 9, 10, 11, 5, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 4, 3, 2, 7, 6, 12, 8, 9, 10, 11, 5, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 4, 3, 2, 7, 6, 12, 8, 9, 10, 11, 5, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 4, 3, 2, 7, 6, 12, 8, 9, 10, 11, 5, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 4, 3, 2, 7, 6, 12, 8, 9, 5, 11, 10, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 4, 3, 2, 7, 6, 12, 8, 9, 5, 11, 10, 13, 14, 15, 16, 17, 18, 19]
[0, 1, 4, 3, 2, 7, 6, 12, 8, 9, 5, 11, 10, 13, 14, 15, 16, 17, 18, 19]
>>> print(k)
[0, 1, 4, 3, 2, 7, 6, 12, 8, 9, 5, 11, 10, 13, 14, 15, 16, 17, 18, 19]

That's because you create copies of the original list by lst[:mid], lst[mid:]. A solution is to pass to change() the same list and (separately) the range to process.

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