#!/usr/bin/env python
import xlrd
from zipfile import zipfile
datafile = "2013_ERCOT_Hourly_Load_Data.xls"
def open_zip(datafile):
with ZipFile('{0}.zip'.format(datafile),'r') as myzip:
myzip.extractall()
def parse_file(datafile):
workbook = xlrd.open_workbook(datafile)
sheet = workbook.sheet_by_index(0)
data = [[sheet.cell_value(r, col)
for col in range(sheet.ncols)]
for r in range(sheet.nrows)]
cv = sheet.col_value(1, start_rowx=1, end_rowx=None)
maxval = max(cv)
minval = min(cv)
maxpos = cv.index(maxval) + 1
minpos = cv.index(minval) + 1
maxtime = sheet.cell_value(maxpos, 0)
realtime = xlrd.xldate_as_tuple(maxtime, 0)
mintime = sheet.cell_value(minpos, 0)
realmintime = xlrd.xldate_as_tupple(mintime, 0)
data = {
'maxtime':(0,0,0,0,0,0),
'maxvalue': 0,
'mintime': (0,0,0,0,0,0),
'minvalue': 0,
'avgcoast': 0
}
return data
def test():
open_zip(datafile)
data = parse_file(datafile)
assert data['maxtime'] == (2013, 8, 13, 17, 0, 0)
assert round(data['maxvalue'], 10) == round(18779.02551, 10)
Reading Excel file
import xlrd datafile = "2013_ERCOT_Hourly_Load_Data.xls". def parse_file(datafile): workbook = xlrd.open_workbook(datafile) sheet = workbook.sheet_by_index(0) data = [[sheet.cell_value(r, col) for col in range(sheet.ncols)] for r in range(sheet.nrows)] print "\nList Comprehension" print "data[3][2]:", print data[3][2] print "\nCells in a nested loop:" for row in range(sheet.nrows): for col in range(sheet.ncols): if row == 50: print sheet.cell value(row, col).
import xlrd
datafile = "2013_ERCOT_Hourly_Load_Data.xls".
def parse_file(datafile):
workbook = xlrd.open_workbook(datafile)
sheet = workbook.sheet_by_index(0)
data = [[sheet.cell_value(r, col)
for col in range(sheet.ncols)]
for r in range(sheet.nrows)]
data = {
'maxtime': (0, 0, 0, 0, 0, 0),
'maxvalue': 0,
'mintime': (0, 0, 0, 0, 0, 0),
'minvalue': 0,
'avgcoast': 0
}
return data
data = parse_file(datafile)
assert data['maxtime'] == (2013, 8, 13, 17, 0, 0)
assert round(data['maxvalue'], 10) == round(18779,02551, 10)
Using CSV Module
import os import pprint import csv DATADIR = "" DATAFILE = "beatles-diskography.csv" def parse_csv(datafile): data = [] n = 0 with open(datafile,'rb') as sd: r = csv.DictReader(sd) for line in r: data.append(line) return data if __name__ == '__main__': datafile = os.path.join(DATADIR, DATAFILE) parse_scv(datafile) d = parse_csv(datafile) pprint.pprint(d)
Parsing CSV Files
import os
DATADIR = ""
DATAFILE = "beatles-diskography.csv"
def parse_file(datafile):
data = []
with open(datafile, "r") as f:
header = f.readline().split(",")
counter = 0
for line in f:
if counter == 10:
break
fields = line.split(",")
entry = {}
for i, value in enumerate(fields):
entry[header[i].strip()] = value.strip()
data.append(entry)
counter += 1
return data
def test():
# a simple test of your implemetation
datafile = os.path.join(DATADIR, DATAFILE)
d = parse_file(datafile)
firstline = {'Title': 'Please Please Me', 'UK Chart Position': '1', 'Label': 'Parlophone(UK)', 'Released': '22 March 1963', 'US Chart Position': '-', 'RIAA Certification': 'Platinum', 'BPI Certification': 'Gold'}
tenthline = {'Title': '', 'UK Chart Position': '1', 'Label': 'Parlophone(UK)', 'Released': '10 July 1964', 'US Chart Position': '-', 'RIAA Certification': '', 'BPI Certification': 'Gold'}
assert d[0] == firstline
assert d[9] == tenthline
Title,Released,Label,UK Chart Position,US Chart Position,BPI Certification,RIAA Certification Please Please Me,22 March 1963,Parlophone(UK),1,-,Gold,Platinum With the Beatles,22 November 1963,Parlophone(UK),1,-,Platinum,Gold Beatlemania! With the Beatles,25 November 1963,Capitol(CAN),-,-,, Introducing... The Beatles,10 January 1964,Vee-Jay(US),-,2,, Meet the Beatles!,20 January 1964,Capitol(US),-,1,,5xPlatinum Twist and Shout,3 February 1964,Capitol(CAN),-,-,, The Beatles' Second Album,10 April 1964,Capitol(US),-,1,,2xPlatinum The Beatles' Long Tall Sally,11 May 1964,Capitol(CAN),-,-,, A Hard Day's Night,26 June 1964,United Artists(US)c,-,1,,4xPlatinum ,10 July 1964,Parlophone(UK),1,-,Gold, Something New,20 July 1964,Capitol(US),-,2,,Platinum Beatles for Sale,4 December 1964,Parlophone(UK),1,-,Gold,Platinum Beatles '65,15 December 1964,Capitol(US),-,1,,3xPlatinum Beatles VI,14 June 1965,"Parlophone(NZ), Capitol(US)",-,1,,Platinum Help!,6 August 1965,Parlophone(UK),1,-,Platinum, ,13 August 1965,Capitol(US) c,-,1,,3xPlatinum Rubber Soul,3 December 1965,Parlophone(UK),1,-,Platinum, ,6 December 1965,Capitol(US) c ,-,1,,6xPlatinum Yesterday and Today,15 June 1966,Capitol(US),-,1,,2xPlatinum Revolver,5 August 1966,Parlophone(UK),1,-,Platinum, ,8 August 1966,Capitol(US) c,-,1,,5xPlatinum Sgt. Pepper's Lonely Hearts Club Band,1 June 1967,"Parlophone(UK), Capitol(US)",1,1,3xPlatinum,11xPlatinum Magical Mystery Tour,27 November 1967,"Parlophone(UK), Capitol(US)",31[D],1,Platinum,6xPlatinum The Beatles,22 November 1968,"Apple(UK), Capitol(US)",1,1,Platinum,19xPlatinum Yellow Submarine,13 January 1969,"Apple(UK), Capitol(US)",3,2,Silver,Platinum Abbey Road,26 September 1969,"Apple(UK), Capitol(US)",1,1,2xPlatinum,12xPlatinum Let It Be,8 May 1970,"Apple(UK),United Artists(US)",1,1,Gold,4xPlatinum
reduced satisfaction
def set_preprocessing(num_variables, clauses): rules_applicable = True temp_assignment = [None]*(num_variables*1) while rules_applicable == True: rules_applicable = False variable_counter = [0]*(num_vaiables*1) var_setting = [None]*(num_variable*1) for clause in clauses: for var in clause: avar = abs(var) variable_counter[avar] += 1 var_setting[avar] = (1 if var > else 0) for i, var in enumerate(variable_counter): if var != 1: continue if temp_assignment[i] is not None: continue temp_assignment[i] = var_setting[i] for clause in clauses: assert len(clase) != 0 if len(clause) > 1: continue var = clause[0] avar = abs(var)
cover by tree
def vertex_cover_tree(input_graph):
n = len(input_graph)
assignment = [None]*n
return recursive_vertex_cover(input_graph, assignment)
def recursive_vertex_cover(input_graph, assignment):
n = len(input_graph)
v = -1
for i in range(n):
if assignment[i] == None:
v = i
for j in range(i, n):
if input_graph[i][j] == 1:
if assignment[i] == 0 and assignment[j] == 0:
return float("inf")
if v == -1:
size = 0
for i in range(n):
if assignment[i] == 1:
size += 1
return size
assignment[v] = 0
size_v_0 = recursive_vertext_cover
4color
from fourcolor import graph_is_4colorable def graph_is_3colorbale(g): h = [] for node in g: nn = node + [1] h.append(nn) h.append([1] * (len(g) + 1)) return graph_is_4colorable(h)
Shortest toure
best_tour_length = infinity for each possible ordering of the houses tour_length = 0 for i in range[1,n-1] tour_length = tour_length + distance(house[i], house[i+1]) tour_length = toure_length + distance(house[n], house[1]) best_tour_length = min(best_tour_length, tour_length)
satisfied
def is_satisfied(num_variables, clauses, assignment): for clause in clauses: caluse_satisfied = False for variable in clause: if variable > 0: if assignment[variable] == True: clause_satisfied = True break else: if assignment[-variable] == False: clause_satisfied = True break if clause_satisfied == False: return False return True
Naivete Implemented
from itertools import * def validity_check(cover, graph): assert len(graph) == len(cover) n = len(graph) for i in range(0, n): for j in range(i+1, n): if graph[i][j]==1 and cover[i]!=1 and cover[j]!=1: return False return True def vertex_cover_naive(input_graph): n = len(input_graph) minimum_vertex_cover = n for assignment in product([0, 1], repeat=n): if(validity_check(assignment, input_graph, n)): size = sum(assignment) if minimum_vertex_cover > size: minimum_vertex_cover = size return minimum_vertex_cover def test(): graph = [[0, 1, 1, 1, 1], [1, 0, 0, 0, 1], [1, 0, 0, 1, 1], [1, 0, 1, 0, 0], [1, 1, 1, 1, 0]] asseret vertex_cover_naive(graph) == 3
For each vertex v in G: if_better: assign "1" to v else: assign "0" to v if assignment is valid: if size of assignment is at most k: return "Yest" return "No"