We Keep Coding

Python: how to load json with dict containing range

my python code is about generating a sequence number from a dict keys, and my dict keys are defined with a range using cycle package in itertools module.
working example:
from itertools import cycle
e = {'Apple': cycle(range(1,999)),'Orange': cycle(range(1,999)),'Banana': cycle(range(1,999))}
def SequenceNum(f):
return f'{next(e[f])}'.zfill(3)
X = SequenceNum('Apple')
print(X)
output
001 --> it keeps incrementing in the range specified above in dict `e`
Challenge:
My requirement is to convert this dict of e into a json file. So it will load keys and values by parsing json file.
cat test.json
{
"DATA": {
"Apple": "cycle(range(1,999))",
"Orange": "cycle(range(1,999))",
"Banana": "cycle(range(1,999))"
}
}
(i had to put the dict values inside double quotes to avoid json file loading error.)
code
import json
from itertools import cycle
with open('test.json') as f:
FromJson = json.load(f)
d = FromJson['DATA']
print(d)
def SequenceNum(f):
return f'{next(d[f])}'.zfill(3)
X = SequenceNum('Apple')
i = 1
while i <= 10:
print(i, SequenceNum('Apple'))
i += 1
here new dict is d that loads json file and it will load the values in single quotes.
output
{'Apple': 'cycle(range(1,999))', 'Orange': 'cycle(range(1,999))', 'Banana': 'cycle(range(1,999))'} #THIS IS OUTPUT of 'd' after loading json file
Traceback (most recent call last):
File "c:\Users\chandu\Documents\test.py", line 14, in <module>
print(i, SequenceNum('Apple'))
File "c:\Users\chandu\Documents\test.py", line 12, in SequenceNum
return f'{next(d[f])}'.zfill(3)
TypeError: 'str' object is not an iterator
it is giving error because my dict values are not properly iterable by cycle itertools modules, since they are in quotes. i dont know if there is any other cause for this error.
please help to resolve this error,
Thanks in advance.

If you are sure what each value is, you can do eval with care:
def SequenceNum(f):
return f'{next(eval(d[f]))}'.zfill(3)
Note this is very dangerous to use, because eval evaluates anything that is passed into it and can cause harm.
This also will always fetch first value from iterator as it is evaluated new everytime. To solve, you can:
def SequenceNum(f):
return eval(d[f])
i = 1
seq_iter = SequenceNum('Apple')
while i <= 10:
print(i, f'{next(seq_iter)}'.zfill(3))
i += 1

Why might python be interpreting my dictionary as a list?

I'm writing a program to sort through csv files. It is supposed to pull lines from the files and based on whether a "donor" is already in the dictionary, either add the "donor" to the dictionary or append the information in the line to the old value. I'm getting the error statement:
error statement: File "C:/Users/riley/Desktop/Python Files/MYLATEST1.py", line 27, in
donors[donor] = [[data]]
builtins.TypeError: list indices must be integers or slices, not tuple
I'm new to python, but it seems as if python is interpreting my dictionary as a list. Is that what's going on? If so, why? Thanks for any help!
def createDonorDirect():
listoffiles = glob.glob('C:/Users/riley/Desktop/mydata//*.csv') #glob allows you to create a list of files/folders that match wildcard expression in this case all the csv files in the directory
# Create donors directory
donors = {}
for filename in listoffiles:
with open(filename) as file:
for line in file:
# line processing stuff
data = line.split(',')
donor = ''.join(data[3,5,7])
# populate data structure
if donor in donors:
donors[donor].append(data)
else:
donors[donor] = [[data]]

The reason for the error is you are assigning donor to tuple value as key, which is wrong here since tuple content multiple values.
sample problem regeneration with code:-
>>> data=['HI','Hello','How','are','you','my','name','is']
>>> donor = ''.join(data[3,5,7])
Traceback (most recent call last):
File "<pyshell#34>", line 1, in <module>
donor = ''.join(data[3,5,7])
**TypeError: list indices must be integers or slices, not tuple**
>>>
second simplified code:-
>>> data[3,5,7]
Traceback (most recent call last):
File "<pyshell#35>", line 1, in <module>
data[3,5,7]
TypeError: list indices must be integers or slices, not tuple

Tuple declaration can be little confusing sometimes.
For example: SOME_CONSTANT = 1, is same as SOME_CONSTANT = (1, ) . Both are a tuple.
On the other hand, SOME_CONSTANT = (1) will be same as SOME_CONSTANT = 1. Both are an integer.
In your case you just need to change:
donor = ''.join(data[3,5,7])
to
donor = ''.join(data[3] + data[5] + data[7])
Example:
data=['A','B','C','D','E','F','G','H']
print ''.join(data[3] + data[5] + data[7])
DFH

List range is being taken as tuple rather than integers

I am trying to fetch elements from a list as per following code:
"data" is a string containing some data from which i am taking out values of start and end offset.
I am then multiplying the start and end Offset by 4 to calculate start,endOffsetAsPerPage.
startOffset = data.split(",,")[1].split(":")[1];
endOffset = data.split(",,")[2].split(":")[1];
startOffsetAsPerPage = int(startOffset)*4;
endOffsetAsPerPage = int (endOffset)*4;
FilteredData = CassandraData[int(startOffsetAsPerPage),int(endOffsetAsPerPage)];
While executing, i am facing following error:
Traceback (most recent call last):
File "CassandraDataAPIResultValidator.py", line 55, in <module>
FilteredData = CassandraData[int(startOffsetAsPerPage),int(endOffsetAsPerPage)];
TypeError: list indices must be integers, not tuple
Can you please help here.
Thanks in advance.

You are using a comma:
FilteredData = CassandraData[int(startOffsetAsPerPage),int(endOffsetAsPerPage)]
# ^
A comma there makes it a tuple, not a slice.
Use a colon instead:
FilteredData = CassandraData[int(startOffsetAsPerPage):int(endOffsetAsPerPage)]
# ^
Note that Python doesn't need to use semicolons at the ends of lines.

How to put an dictionary to an array?

I want to split the History_Data with , and put into an dictionary , then put the dictionary to a one dimension array then access them . But it seems have some error . How can I solve that?
here is my code
History_Data = ("2004/01/20,000006,29,28,13,33,34,32,43",
"2004/01/18,000005,36,22,44,34,46,29,37",
"2004/01/16,000004,02,13,34,44,06,40,14",
"2004/01/14,000003,29,28,13,33,34,32,43",
"2004/01/12,000002,32,15,14,29,39,20,43",
"2004/01/10,000001,30,29,18,34,19,28,12")
Dataset = ()
for Line in History_Data:
Item = {}
Parts = Line.split(",")
Item['date'] = Parts[0]
Item['serial'] = Parts[1]
Item['numbers'] = Parts[2:len(Parts)]
Dataset.append(Item)
for Element in Dataset:
print(Element)
Error message
Traceback (most recent call last):
File ".\1.py", line 18, in <module>
Dataset.append(Item)
AttributeError: 'tuple' object has no attribute 'append'

tuple is an immutable type in Python so gets no method append. For your need, use a list, Dataset = [], not a tuple, Dataset = ().

strip ' from all members in a list

Ok, so I converted each line in a text file into a member of a list by doing the following: chkseq=[line.strip() for line in open("sequence.txt")] So when I print chkseq I get this: ['3','3'] What I would like is for it to instead look like this: [3,3] I know this is possible, I'm just unsure of how! I need them to be intergers, not strings. So if all else fails, that is my main goal in this: create a list from a .txt file whose members are intergers (which would be all the .txt file contained). Thanks!! -OSFTW

It looks like you want to interpret the strings as integers. Use int to do this:
chkseq = [int(line) for line in open("sequence.txt")]
It can also be written using map instead of a list comprehension:
chkseq = map(int, open("sequence.txt"))

iterate over the elements of your list and print them out with your preferred formatting rather than relying on the default formatting when printing the whole list at once.

Say your array is called input, and you want to store the value in an array called chkseq, your code would be:
chkseq = [int(i) for i in input]
Or, if you wanted to do everything all in one line:
chkseq = [int(i.strip()) for i in open("sequence.txt")]

Passing a string to the int constructor will attempt to turn it into a int.
>>> int('3')
3
>>> int('foo')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: 'foo'