Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>You have several errors in your code:</p> <ol> <li>Not ignoring the first line of your csv file which contains 'name' and 'date'.</li> <li>Using strings to store dates instead of the <code>date</code> type.</li> <li>Attempting to subtract one string from another.</li> <li>Modifying items in <code>datedict</code> without first checking that they exist.</li> <li>The slashes in 1/1/2003 are going to be treated as divide signs and the result will be 0.</li> </ol> <p>Here is what your code would look like with these errors fixed:</p> <pre><code>import csv from collections import defaultdict import datetime from datetime import date import math def weeks(filename, start_date): # The defaultdict class will create items when a key is accessed that does # not exist datedict = defaultdict(set) with open(filename, 'r') as csvfile: filereader = csv.reader(csvfile, 'excel') read_header = False for row in filereader: # Ignore the first row of the file if not read_header: read_header = True continue # Strip out any whitespace cells = [col.strip() for col in row] name = cells[0] date_str = cells[1] # Parse the date string into a date row_date = datetime.datetime.strptime(date_str, '%d/%m/%Y').date() # Calculate the difference between dates delta = start_date-row_date # Convert from days to weeks, you could use math.floor() here if # needed delta_weeks = int(math.ceil(delta.days / 7.0)) datedict[name].add(delta_weeks) return datedict date_dict = weeks('a.csv', start_date=date(year=2013, month=1, day=1)) for name, dates in date_dict.iteritems(): print name, list(dates) </code></pre> <p>This prints out:</p> <pre><code>bil [351, 254] sam [519, 182] Mali [179] </code></pre> <p>You should be able to figure out how to get it to print 'weeks'.</p>
    singulars
    1. This table or related slice is empty.
    1. POHow can I subtract a fixed date from a columns of date in excel file using Python?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USNathan Villaescusa
    1. USNathan Villaescusa
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POHow can I subtract a fixed date from a columns of date in excel file using Python?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COYou must have extra columns in the file, or it is not being read correctly by csv. Try printing out the contents of `row`.
      singulars
      1. PO
      1. USNathan Villaescusa
    2. COCheck out the updated code.
      singulars
      1. PO
      1. USNathan Villaescusa
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload