Help accessing elements of list of dictionaries

[Milfredo]

I have filled a list with dictionaries in the following code. I have watched at least 5 videos looking for the answer. How can I access elements of individual dictionaries residing within that list?

def load_racefiles() :

	count = 0
	master_race_file = []
	rows = 100
	columns = 100
	horse_array = [0 for i in range(rows)] 
	file_name = StringVar()
	f_name = StringVar()
	#file_dir = (r"C:\2020")
	fd =    open("dirpath", "r") 
	file_dir = (fd.read())
	fd.close()
	os.chdir(file_dir)
	for f in os.listdir(file_dir): 
		file_name, file_ext = os.path.splitext(f)
		f_name = file_name + file_ext
		file_name = file_name.strip()[3:]
		line_counter = 0
		if file_name == Race_date and file_ext == ".jcp":
			with open(f_name, "r") as csv_file:
				csv_reader = csv.reader(csv_file)
				
				for line in csv_reader:
					
											

				
					
					h = {'track' : line[0],
					'race_number' : line[2], 
					'todays_surface' : line[6],
					'race_type' : line[8], 
					'todays_purse' : line[11],
					'trn_starts_curmeet' : line[28],
					'trn_wins_curmeet' : line[29],
					'jock_sts_curmeet' : line[34],
					'jock_wins_curmeet' : line[35],
					'trn_starts_prevyear' : line[1151],
					'trn_wins_prevyear' : line[1152],
					'jock_sts_prevyear' : line[1161],
					'jock_wins_prevyear' : line[1162],
					'trn_starts_curyear' : line[1146],
					'trn_wins_curyear' : line[1147],
					'jock_sts_curyear' :  line[1156],
					'jock_wins_curyear':  line[1157],
					'morn_line': line[43],
					'horse_name' : line[44],
					'year_of_birth' : line[45],
					'hstarts_todays_dist' : line[64],
					'hwins_todays_dist ' : line[65],
					'hstarts_todays_track' : line[69],
					'hwins_todays_track' :line[70],
					'hstarts_turf' : line[74],
					'hwins_turf' : line[75],
					'hstarts_mud' : line[79],
					'hwins_mud' : line[80],
					'hstarts_cur_yr' : line[84],
					'hwins_cur_yr' : line[85],
					'hstarts_prev_yr' : line[90],
					'hwins_prev_yr' : line[91],
					'hstarts_life' : line[96],
					'hwins_life' : line[97], 
					'days_since' : line[223],
					'power_rating' : line[250],
					'dist_yards1' : line[315],
					'dist_yards2' : line[316],
					'dist_yards3' : line[317],
					'dist_yards4' : line[318],
					'dist_yards5' : line[319],
					'dist_yards6' : line[320],
					'dist_yards7' : line[321],
					'dist_yards8' : line[322],
					'dist_yards9' : line[323],
					'dist_yards10' : line[324],
					'surface1' : line[325],
					'surface2' : line[326],
					'surface3' : line[327],
					'surface4' : line[328],
					'surface5' : line[329],
					'surface6' : line[330],
					'surface7' : line[321],
					'surface8' : line[332], 
					'surface9' : line[333],
					'surface10' : line[334],
					'entrants1' : line[345],
					'entrants2' : line[346],
					'entrants3' : line[347],
					'entrants4' : line[348],
					'entrants5' : line[349],
					'entrants6' : line[350],
					'entrants7' : line[351],
					'entrants8' : line[352],
					'entrants9' : line[353],
					'entrants10' : line[354],
					'first_call1' :  line[575],
					'first_call2' : line[576],
					'first_call3' : line[577],
					'first_call4' : line[578],
					'first_call5' : line[579],
					'first_call6' : line[580],
					'first_call7' : line[581],
					'first_call8' : line[582],
					'first_call9' : line[583],
					'first_call10' : line[584],
					'second_call1' : line[585],
					'second_call2' : line[586],
					'second_call3' : line[587],
					'second_call4' : line[588],
					'second_call5' : line[589],
					'second_call6' : line[590],
					'second_call7' : line[591],
					'second_call8' : line[592],
					'second_call9' : line[593],
					'second_call0' : line[594],
					'finish_Position' : line[615],
					'last_peed' : line[845],
					'speed_2back' : line[846],
					'speed_3back' : line[847],
					'bestSpeed_Life' : line[1327],
					'bestSpeed_Fasttrack' : line[1177],
					'bestSpeed_turf' : line[1178],
					'bestSpeed_offtrack' : line[1179],
					'bestSpeed_dist' : line[1180],
					'race_conditions' : line[15],
					'todays_race_classification' : line[10]

					

 				
 						}

					master_race_file.append(h ) 

[bowlofred]

If you have a list of dictionaries, you access by giving the list index first, then the dictionary key.

list_of_dicts = [{'a': 1,
                  'b': 2,
                  'c': 3,
                 },
                 {'a': 4,
                  'b': 5,
                  'c': 6,
                 },
                 {'a': 7,
                  'b': 8,
                  'c': 9,
                 },
                ]
print(list_of_dicts[0]['b'])  # first list element, dict key 'b'
print(list_of_dicts[2]['b'])  # third list element, dict key 'b'

Output:
2
8

[Milfredo]

Thank you. I defined the list master_race_file = [] in function load_racefiles() . How do I access the list outside of the function? When I try I get error master_race_file is not defined, or this error

$ python hello2.py
Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Users\Milford\AppData\Local\Programs\Python\Python38-32\lib\tkinter\__init__.py", line 1883, in __call__
return self.func(*args)
File "hello2.py", line 1279, in load_racefiles
print(master_race_file[0]['horse_name'])
IndexError: list index out of range

Thanks in advance

[bowlofred]

Usually you would return the data structure to the calling program. Then the caller would assign it to a variable.

def load_racefiles():
    # calculate master_race_file
    return master_race_file


master_race_file = load_racefiles()
print(master_race_file[0]['horse_name'])

[Milfredo]

I changed the code as you suggested. Here is the result... where as before adding your code no error message.


$ python hello2.py
Traceback (most recent call last):
File "hello2.py", line 1283, in <module>
master_race_file = load_racefiles()
File "hello2.py", line 1164, in load_racefiles
if file_name == Race_date and file_ext == ".jcp":
NameError: name 'Race_date' is not defined

---

I changed the code and put it like this. And it works. But problem is I am still in the load_races function

master_race_file.append(h ) 
			
				my_labeldone= Label( text ="Downloading Complete", fg= "black", font = ("sans_serif" , 16)).place(x=500, y=500)
	print( master_race_file[0]['todays_race_classification'])

I wanted to access the info outside the function.

[bowlofred]

Do you understand the snippet I posted? The error you have shown now isn't related. However, it's not feasible for us to try to debug a 1200+ line program. You should try to cut it down to a much simpler example that shows your problem that others can run.

[Milfredo]

Ok. Hopefully this will be better.

my_button1 = Button(root, text = "Load Race Files", width = 15, command = load_racefiles) 
my_button1.place(x=443, y=150)

def load_racefiles() :
	global Race_date

	count = 0
	master_race_file = []
	rows = 100
	columns = 100
	horse_array = [0 for i in range(rows)] 
	file_name = StringVar()
	f_name = StringVar()
	
	fd =    open("dirpath", "r") 
	file_dir = (fd.read())
	fd.close()
	os.chdir(file_dir)
	for f in os.listdir(file_dir): 
		file_name, file_ext = os.path.splitext(f)
		f_name = file_name + file_ext
		file_name = file_name.strip()[3:]
		line_counter = 0
		if file_name == Race_date and file_ext == ".jcp":
			with open(f_name, "r") as csv_file:
				csv_reader = csv.reader(csv_file)
				
				for line in csv_reader:

                     h = {'track' : line[0],
                     'horse_name' : line[44]
                          }
                    master_race_file.append(h ) 
					
				my_labeldone= Label( text ="Downloading Complete", fg= "black", font = ("sans_serif" , 16)).place(x=500, y=500)

This all works. Now I need to access the dictionaries to see if the track name and the race date selected by the user previous to load_files function is called are equal so I can put that line in a separate smaller list so I can then manipulate the data.

I hope this is easier to deal with.