So I create an empty pandas df, where I initialize all the cell values to empty lists, except the diagonals, which are set to math.inf
The indexes are the start position, and the column headers are the end position
I want to get the start and end positions, and the difference between the days to get from start to end, and put that value in df.loc[start, end] by using append. But for some reason, every single cell in the df is getting updated, and i dont know why
My code is shown below
self.status_dict = {'nvc': 'At NVC', 'issued': 'Issued', 'ready': 'Ready', 'ar_ds260': 'Action required: Complete Form DS-260', 'transit': 'In Transit', 'refused': 'Refused', 'ar_doc': 'Action required: Submit requested documents', 'admin_process': 'Administrative Processing', 'expire_soon': 'Expiring Soon', 'app_received': 'Application Received', 'ar_pay': 'Action required: Pay fees', 'return_nvc': 'Returned to NVC', 'transfer': 'Transfer in Progress', 'expired': 'Expired', 'ar_pay_miss': 'Action required: Pay missing fees', 'no_action': 'No action required: Review in process', 'no_status': 'No Status', 'ar_choose': 'Action required: Choose an agent' }self.status_dict_lookup = {'At NVC': 'nvc', 'Issued': 'issued', 'Ready': 'ready', 'Action required: Complete Form DS-260': 'ar_ds260', 'In Transit': 'transit', 'Refused': 'refused', 'Action required: Submit requested documents': 'ar_doc', 'Administrative Processing': 'admin_process', 'Expiring Soon': 'expire_soon', 'Application Received': 'app_received', 'Action required: Pay fees': 'ar_pay', 'Returned to NVC': 'return_nvc', 'Transfer in Progress': 'transfer', 'Expired': 'expired', 'Action required: Pay missing fees': 'ar_pay_miss', 'No action required: Review in process': 'no_action', 'No Status': 'no_status', 'Action required: Choose an agent': 'ar_choose' }shape = len(self.status_dict_lookup) const_arr = [[]] * shape keys = self.status_dict.keys() df_dict = dict() for key in keys: df_dict[key] = const_arr df = pd.DataFrame(df_dict) df = df.set_index(pd.Index(keys)) for key in keys: df.loc[key, key] = math.inf # cases = self.cases cases = {1044: [['Action required: Submit requested documents', '2021-12-18'], ['At NVC', '2022-02-03'], ['In Transit', '2022-02-14'], ['Ready', '2022-02-15'], ['Refused', '2022-03-10'], ['Administrative Processing', '2022-03-12'], ['Issued', '2022-03-14']]} for _, val in cases.items(): print(val[0], val[1]) print(val[0][1], val[1][1]) for i in range(len(val) - 1): temp = [] start = val[i][0] end = val[i + 1][0] start_time = datetime.strptime(val[i][1], '%Y-%m-%d') end_time = datetime.strptime(val[i + 1][1], '%Y-%m-%d') diff = end_time - start_time temp = df[self.status_dict_lookup[start]][self.status_dict_lookup[end]] print(temp) temp.append(diff.days) df.loc[self.status_dict_lookup[start], self.status_dict_lookup[end]] = temppart of the output of the df is shown below:
nvc issued nvc inf [47, 11, 1, 23, 2, 2] issued [47, 11, 1, 23, 2, 2] inf ready [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] ar_ds260 [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] transit [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] refused [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] ar_doc [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] admin_process [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] expire_soon [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] app_received [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] ar_pay [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] return_nvc [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] transfer [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] expired [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] ar_pay_miss [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] no_action [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] no_status [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] ar_choose [47, 11, 1, 23, 2, 2] [47, 11, 1, 23, 2, 2] So for the first example,
start = Action required: Submit requested documents
end = At NVC
diff = 47
So i want it to store just 47 as a list in df[ar_doc][nvc]. But it is storing the difference of all days in all the cells
Why does this happen and how to fix it?
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Answer
All your pandas data are referencing the same list. You should change how you initialize the DataFrame. You should create a new list in each cell.
Try:
df = pd.DataFrame({k: [list() for _ in range(len(status_dict))] for k in status_dict}, index=status_dict.keys())for key in keys: df.at[key, key] = math.infSeparately, since you’re already using pandas, you don’t need to use datetime to parse dates. You can reduce your loop to the following:
for _, val in cases.items(): for i in range(len(val)-1): diff = pd.to_datetime(val[i][1], format='%Y-%m-%d') - pd.to_datetime(val[i + 1][1], format='%Y-%m-%d') df.at[status_dict_lookup[val[i][0]], status_dict_lookup[val[i+1][0]]] += [diff.days]