Pivot Table to Dictionary - python

I have this pivot table:
[in]:unit_d
[out]:
units
store_nbr item_nbr
1 9 27396
28 4893
40 254
47 2409
51 925
89 157
93 1103
99 492
2 5 55104
11 655
44 117125
85 106
93 653
I want to have a dictionary with 'store_nbr' as the key and 'item_nbr' as the values.
So, {'1': [9, 28, 40,...,99], '2': [5, 11 ,44, 85, 93], ...}

I'd use groupby here, after resetting the index to make it into columns:
>>> d = unit_d.reset_index()
>>> {k: v.tolist() for k, v in d.groupby("store_nbr")["item_nbr"]}
{1: [9, 28, 40, 47, 51, 89, 93, 99], 2: [5, 11, 44, 85, 93]}

Related

Plotting grouped multi-index data with a For loop

I am trying to produce multiple plots from a for loop.
My dataframe is multi-indexed as below:
temperature depth
ID Month
33 2 150 95
3 148 79
4 148 54
5 155 77
55 2 168 37
3 172 33
4 107 32
5 155 77
61 2 168 37
3 172 33
4 107 32
5 155 77
I want to loop through each ID and plot:
Temperature as a line against Month (x-axis)
Depth as a bar against Month (x-axis)
I want these to be on the same plot.
This is what I have so far:
# group the dataframe
grp = df.groupby([df.index.get_level_values(0), df.index.get_level_values(1)])
# create empty plots
fig, ax = plt.subplots()
# create an empty plot for combining with ax
ax2 = ax.twinx()
# for loop
for ID, group in grp:
ax.bar(df.index.get_level_values(1), group["temperature"], color='blue', label='Release')
ax2.plot(df.index.get_level_values(1), group["depth"], color='green', label='Hold')
ax.set_xticklabels(df.index.get_level_values(1))
plt.savefig("value{y}.png".format(y=ID))
next
dataframe reprex:
import pandas as pd
index = pd.MultiIndex.from_product([[33, 55, 61],['2','3','4', '5']], names=['ID','Month'])
df = pd.DataFrame([[150, 95],
[148, 79],
[148, 54],
[155, 77],
[168, 37],
[172, 33],
[107, 32],
[155, 77],
[168, 37],
[172, 33],
[107, 32],
[155, 77]],
columns=['temperature', 'depth'], index=index)

How to print prime numbers in a tabular format

my goal is to print prime numbers in a tabular format, instead of printing one value each line. so far all my attempts have ended in either lines, or misprinted tables.
start = int(input("Start number: "))
end = int(input("End number: "))
if start < 0 or end < 0:
print("Start and End must be positive.")
start = int(input("Start number: "))
end = int(input("End number: "))
if end < start:
print("End must be greater than Start number: ")
start = int(input("Start number: "))
end = int(input("End number: "))
prime = True
for num in range(start,end+1):
if num > 1:
for i in range(2,num):
if num % i == 0:
break
else:
num = print(num)
the one i have here can only print it line by line
#start number: 1
#end number: 100
# 2 3 5 7 11 13 17 19 23 29
#31 37 41 43 47 53 59 61 67 71
#73 79 83 89 97
This can be done with str.rjust or its friends
>>> "2".rjust(3)
' 2'
>>>
first we gather the numbers we want to print and calculate how many characters it take the biggest of them and add one to that value, that result is the one we will use for the rjust
>>> nums=[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]
>>> j = len(str(max(nums))) + 1
>>>
now we pick how many we want to print per line
>>> linesize = 10
>>>
and finally we make use of print keyword-only arguments end to control when to print in the same line or not and enumerate to control how many we have already printed
>>> for i,p in enumerate(nums,1):
print( str(p).rjust(j), end="" )
if i%linesize==0:
print() #to go to the next line
2 3 5 7 11 13 17 19 23 29
31 37 41 43 47 53 59 61 67 71
73 79 83 89 97
>>>
You could use str.format and implement a reusable solution using a generator:
from math import floor
def tabular(records, line_width=42, sep_space=3):
width = len(str(max(records))) + sep_space
columns = floor(line_width/width)
for i in range(0, len(records), columns):
row_records = records[i:i+columns]
row_format = ("{:>" + str(width) + "}") * len(row_records)
yield row_format.format(*row_records)
# test data / prime numbers
numbers = [
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37,
41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83,
89, 97
]
for row in tabular(numbers):
print(row)
# 2 3 5 7 11 13 17 19
# 23 29 31 37 41 43 47 53
# 59 61 67 71 73 79 83 89
# 97
Example with some other numbers:
for row in tabular(list(range(0, 1600, 50)), 79, 2):
print(row)
# 0 50 100 150 200 250 300 350 400 450 500 550 600
# 650 700 750 800 850 900 950 1000 1050 1100 1150 1200 1250
# 1300 1350 1400 1450 1500 1550
Example with str.format but without using a generator:
# test data / prime numbers
numbers = [
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37,
41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83,
89, 97
]
width = len(str(max(numbers))) + 3
for i in range(0, len(numbers), 10):
row_records = numbers[i:i+10]
row_format = ("{:>" + width + "}") * len(row_records)
print(row_format.format(*row_records))
# 2 3 5 7 11 13 17 19 23 29
# 31 37 41 43 47 53 59 61 67 71
# 73 79 83 89 97

Maximum average of n consecutive values in DataFrame

I want to find maximum average of n conseсutive values in DataFrame.
import pandas as pd
list1 = [120, 130, 135, 140, 170, 131, 131, 151, 181, 191, 200, 210, 220, 170, 160, 151, 120, 140, 170, 173]
list2 = [80, 81, 82, 82, 82, 83, 84, 84, 85, 85, 85, 86, 87, 88, 89, 90, 90, 90, 91, 91 ]
df = pd.DataFrame(zip(list1, list2), columns=['value1', 'value2'])
df['interval'] = 0
interval_duration = 3 # set interval duration
number_of_intervals = 4 # set number of intervals
# I found only a way with for loop:
for x in range(1, number_of_intervals + 1):
max_average_interval = sum(df['value1'][0 : interval_duration]) / interval_duration
item_max = 0
for item in range(len(df['value1']) - interval_duration + 1):
if sum(df['interval'].loc[item : item + interval_duration - 1]) == 0:
if max_average_interval < sum(df['value1'][item : item + interval_duration]) / interval_duration:
max_average_interval = sum(df['value1'][item : item + interval_duration]) / interval_duration
item_max = item
df['interval'].loc[item_max : item_max + interval_duration - 1] = x
Result:
value1 value2 interval
0 120 80 0
1 130 81 0
2 135 82 0
3 140 82 0
4 170 82 0
5 131 83 0
6 131 84 0
7 151 84 2
8 181 85 2
9 191 85 2
10 200 85 1
11 210 86 1
12 220 87 1
13 170 88 4
14 160 89 4
15 151 90 4
16 120 90 0
17 140 90 3
18 170 91 3
19 173 91 3
where in the interval column:
1 - first maximum interval of consecutive values
2 - second maximum interval of consecutive values
and so on.
Question. If there is a more efficient way to do this? That's matter because I can have thousands and thousands of values.
Updated
Updated again..

Group by continuous indexes in Pandas DataFrame

I'm working on code for sensors data analysis using python.
I'm taking rows from DataFrame (of gyro data in the example) according to some condition.
import pandas as pd
gyro = pd.read_csv("gyroOutput.csv")
above = gyro[gyro['gyro_z'] > 0.30]
above
Out[162]:
gyro_x gyro_y gyro_z elapsed
27 0.026632 0.021305 0.305731 4.927
28 0.017044 0.011718 0.344080 5.115
29 0.008522 0.013848 0.380299 5.289
30 0.006392 0.026632 0.412257 5.470
31 0.007457 0.005326 0.448476 5.643
32 -0.004261 0.012783 0.465521 5.822
33 -0.001065 0.000000 0.452737 6.002
34 0.009587 0.006392 0.445281 6.181
35 0.010653 0.001065 0.412257 6.361
36 0.006392 0.003196 0.373908 6.543
37 -0.006392 0.007457 0.320645 6.722
108 -0.036219 0.052198 0.323840 19.470
109 -0.061785 -0.001065 0.389887 19.654
110 -0.049002 0.018109 0.453803 19.835
111 -0.038350 0.078830 0.513458 20.015
112 -0.034088 0.011718 0.555003 20.192
113 -0.005326 -0.001065 0.607201 20.374
114 0.009587 0.058590 0.629571 20.553
115 0.038350 -0.029827 0.598679 20.727
116 0.006392 0.013848 0.546481 20.907
117 0.007457 0.030893 0.478304 21.086
118 0.012783 -0.035154 0.446346 21.266
119 0.005326 -0.026632 0.367516 21.444
352 0.007457 0.028762 0.313188 63.284
353 0.006392 -0.011718 0.332363 63.463
354 0.008522 0.030893 0.378169 63.643
355 -0.015979 0.039415 0.409062 63.822
356 -0.009587 -0.022371 0.423975 64.002
357 -0.008522 0.023436 0.450607 64.181
358 -0.011718 0.047937 0.453803 64.361
That result data frame (above) holds groups of continuous indexes rows. For example, lines 27-37.
I want to get all those group's, couldn't find any way to do it using DataFrame.groupby or any other function.
I could iterate over the rows and separate them myself, but maybe there's some simpler way using pandas functions.
IIUC:
In [294]: df.groupby(df.index.to_series().diff().ne(1).cumsum()).groups
Out[294]:
{1: Int64Index([27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37], dtype='int64'),
2: Int64Index([108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119], dtype='int64'),
3: Int64Index([352, 353, 354, 355, 356, 357, 358], dtype='int64')}

Euler Project #18 - Pythonic approach

I'm trying to solve the 18th problem from Project Euler but I'm stuck in the solution. Doing it in a paper I get the same results but I know the answer has a difference of 10 between what I'm getting.
By starting at the top of the triangle below and moving to adjacent numbers on the row below, the maximum total from top to bottom is 23.
3
7 4
2 4 6
8 5 9 3
That is, 3 + 7 + 4 + 9 = 23.
Find the maximum total from top to bottom of the triangle below:
75
95 64
17 47 82
18 35 87 10
20 04 82 47 65
19 01 23 75 03 34
88 02 77 73 07 63 67
99 65 04 28 06 16 70 92
41 41 26 56 83 40 80 70 33
41 48 72 33 47 32 37 16 94 29
53 71 44 65 25 43 91 52 97 51 14
70 11 33 28 77 73 17 78 39 68 17 57
91 71 52 38 17 14 91 43 58 50 27 29 48
63 66 04 68 89 53 67 30 73 16 69 87 40 31
04 62 98 27 23 09 70 98 73 93 38 53 60 04 23
NOTE: As there are only 16384 routes, it is possible to solve this problem by trying every route. However, Problem 67, is the same challenge with a triangle containing one-hundred rows; it cannot be solved by brute force, and requires a clever method! ;o)
Here is my code
filename = "triangle.txt"
f = open(filename,"r+")
total = 0
#will store the position of the maximum value in the line
index = 0
#get the first pyramid value
total = [int(x) for x in f.readline().split()][0]
#since it's only one value, the position will start with 0
current_index = 0
# loop through the lines
for line in f:
# transform the line into a list of integers
cleaned_list = [int(x) for x in line.split()]
# get the maxium value between index and index + 1 (adjacent positions)
maximum_value_now = max(cleaned_list[current_index],cleaned_list[current_index + 1])
#print maximum_value_now
# stores the index to the next iteration
future_indexes = [ind for (ind,value) in enumerate(cleaned_list) if value == maximum_value_now]
# we have more that 2 values in our list with this maximum value
# must return only that which is greater than our previous index
if (len(future_indexes) > 1):
current_index = [i for i in future_indexes if (i >= current_index and i <= current_index + 1)][0]
else:
#only one occurence of the maximum value
current_index = future_indexes[0]
# add the value found to the total sum
total = total + maximum_value_now
print total
Thanks!
First of all, read the entire triangle into a 2d structure. It is handy to note that we can do an affine transformation to the triangle and therefore use an easier coordinate system:
3 \ 3
7 4 ====\ 7 4
2 4 6 ====/ 2 4 6
8 5 9 3 / 8 5 9 3
It is easy to read this into a jagged array in Python:
with open(filename, 'r') as file:
rows = [[int(i) for i in line.split()] for line in file]
Now given x as the horizontal coordinate and y as the vertical coordinate, and them increasing left and down, there are 2 valid moves from (x, y): (x + 1, y + 1) and (x, y + 1). It is as simple as that.
The trick here is now to calculate all the maximum sums for cell in each row. This is called dynamic programming. The maximum sum is then the maximal sum in the last row.
Actually there is no need to remember anything beyond the sums on the just preceding row, and the sums on the current row. To calculate the maximal row sums current_sums', we notice that to arrive to positionxin the latest row, the position must have beenx - 1orx. We choose the maximal value of these, then sum with the currentcell_value`. We can consider any of the numbers outside the triangle as 0 for simplicity as they don't affect the maximal solution here. Therefore we get
with open('triangle.txt', 'r') as file:
triangle = [[int(i) for i in line.split()] for line in file]
previous_sums = []
for row in triangle:
current_sums = []
for position, cell_value in enumerate(row):
sum_from_right = 0 if position >= len(previous_sums) else previous_sums[position]
sum_from_left = (previous_sums[position - 1]
if 0 < position <= len(previous_sums)
else 0)
current_sums.append(max(sum_from_right, sum_from_left) + cell_value)
previous_sums = current_sums
print('The maximum sum is', max(previous_sums))
If you like list comprehensions, the inner loop can be written into one:
current_sums = []
for row in triangle:
len_previous = len(current_sums)
current_sums = [
max(0 if pos >= len_previous else current_sums[pos],
current_sums[pos - 1] if 0 < pos <= len_previous else 0)
+ cell_value
for pos, cell_value in enumerate(row)
]
print('The maximum sum is', max(current_sums))
Here is a simple recursive solution which uses memoization
L1 = [
" 3 ",
" 7 4 ",
" 2 4 6 ",
"8 5 9 3",
]
L2 = [
" 75 ",
" 95 64 ",
" 17 47 82 ",
" 18 35 87 10 ",
" 20 04 82 47 65 ",
" 19 01 23 75 03 34 ",
" 88 02 77 73 07 63 67 ",
" 99 65 04 28 06 16 70 92 ",
" 41 41 26 56 83 40 80 70 33 ",
" 41 48 72 33 47 32 37 16 94 29 ",
" 53 71 44 65 25 43 91 52 97 51 14 ",
" 70 11 33 28 77 73 17 78 39 68 17 57 ",
" 91 71 52 38 17 14 91 43 58 50 27 29 48 ",
" 63 66 04 68 89 53 67 30 73 16 69 87 40 31 ",
"04 62 98 27 23 09 70 98 73 93 38 53 60 04 23 ",
]
class Max(object):
def __init__(self, l):
"parse triangle, initialize cache"
self.l = l
self.t = [
map(int,filter(lambda x:len(x)>0, x.split(" ")))
for x in l
]
self.cache = {}
def maxsub(self, r=0, c=0):
"compute max path starting at (r,c)"
saved = self.cache.get((r,c))
if saved:
return saved
if r >= len(self.t):
answer = (0, [], [])
else:
v = self.t[r][c]
s1, l1, c1 = self.maxsub(r+1, c)
s2, l2, c2 = self.maxsub(r+1, c+1)
if s1 > s2:
answer = (v+s1, [v]+l1, [c]+c1)
else:
answer = (v+s2, [v]+l2, [c]+c2)
self.cache[(r,c)] = answer
return answer
def report(self):
"find and report max path"
m = self.maxsub()
print
print "\n".join(self.l)
print "maxsum:%s\nvalues:%s\ncolumns:%s" % m
if __name__ == '__main__':
Max(L1).report()
Max(L2).report()
Sample output
3
7 4
2 4 6
8 5 9 3
maxsum:23
values:[3, 7, 4, 9]
columns:[0, 0, 1, 2]
75
95 64
17 47 82
18 35 87 10
20 04 82 47 65
19 01 23 75 03 34
88 02 77 73 07 63 67
99 65 04 28 06 16 70 92
41 41 26 56 83 40 80 70 33
41 48 72 33 47 32 37 16 94 29
53 71 44 65 25 43 91 52 97 51 14
70 11 33 28 77 73 17 78 39 68 17 57
91 71 52 38 17 14 91 43 58 50 27 29 48
63 66 04 68 89 53 67 30 73 16 69 87 40 31
04 62 98 27 23 09 70 98 73 93 38 53 60 04 23
maxsum:1074
values:[75, 64, 82, 87, 82, 75, 73, 28, 83, 32, 91, 78, 58, 73, 93]
columns:[0, 1, 2, 2, 2, 3, 3, 3, 4, 5, 6, 7, 8, 8, 9]
To solve the 100-row Project Euler problem 67 we make a small change to __main__
def main():
with file('triangle.txt') as f:
L = f.readlines()
Max(L).report()
if __name__ == '__main__':
main()
Last lines of output:
maxsum:7273
values:[59, 73, 52, 53, 87, 57, 92, 81, 81, 79, 81, 32, 86, 82, 97, 55, 97, 36, 62, 65, 90, 93, 95, 54, 71, 77, 68, 71, 94, 8, 89, 54, 42, 90, 84, 91, 31, 71, 93, 94, 53, 69, 73, 99, 89, 47, 80, 96, 81, 52, 98, 38, 91, 78, 90, 70, 61, 17, 11, 75, 74, 55, 81, 87, 89, 99, 73, 88, 95, 68, 37, 87, 73, 77, 60, 82, 87, 64, 96, 65, 47, 94, 85, 51, 87, 65, 65, 66, 91, 83, 72, 24, 98, 89, 53, 82, 57, 99, 98, 95]
columns:[0, 0, 0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 7, 8, 9, 10, 11, 12, 12, 12, 13, 13, 13, 14, 14, 15, 15, 16, 17, 17, 17, 18, 19, 20, 21, 22, 23, 24, 25, 25, 25, 26, 27, 27, 28, 29, 30, 31, 32, 32, 32, 32, 33, 33, 34, 35, 36, 36, 36, 36, 36, 36, 36, 37, 38, 39, 40, 41, 41, 42, 42, 42, 42, 42, 42, 42, 43, 43, 43, 44, 45, 45, 45, 45, 45, 45, 46, 46, 46, 46, 47, 47, 48, 49, 49, 50, 51, 52, 52, 53]
On my Mac it returns the answer immediately. Here is a timeit measurement:
$ python -m timeit -s 'from p067 import main' main
100000000 loops, best of 3: 0.0181 usec per loop

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