I have data which is in-64 in the Index with values like "01/11/2018" in the index. It is data that has been imported from a csv. I am unable to convert it to a "01-11-2018" format. How do I do this because I get an error message:
'time data 0 does not match format '%Y' (match)'
I got the data from the following website:
https://www.nasdaq.com/symbol/spy/historical
and you can find a ' Download this file in Excel Format ' icon at the bottom.
import datetime
spyderdat.index = pd.to_datetime(spyderdat.index, format='%Y')
spyderdat.head()
How do I format this correctly?
Thanks a lot.
Your format string must match exactly:
import datetime
spyderdat.index = pd.to_datetime(spyderdat.index, format='%d/%m/%Y')
spyderdat.head()
Example w/o spyder:
import datetime
date = "1/11/2018"
print(datetime.datetime.strptime(date,"%d/%m/%Y"))
Output:
2018-11-01 00:00:00
You can strftime this datetime then anyhow you like. See link for formats. Or you store datetimes.
Assuming your input is a string, simply converting the / to - won't fix the issue.
The real problem is that you've told to_datetime to expect the input string to be only a 4-digit year but you've handed it an entire date, days and months included.
If you meant to use only the year portion you should manually extract the year first with something like split.
If you meant to use the full date as a value, you'll need to change your format to something like %d/%m/%Y. (Although I can't tell if your input is days first or months first due to their values.)
The easy way is to try this
datetime.datetime.strptime("01/11/2018", '%d/%m/%Y').strftime('%d-%m-%Y')
Related
This is my data :
dates = np.arange("2018-01-01", "2021-12-31", dtype="datetime64[D]")
I now want to convert from :
"2018-01-01" -> "Jan-01-2018" ["Monthname-day-year"] format
How to i do this ?
Is it possible to initialize this in the way we want to convert ?
Can i use something like:
for i in dates:
i = i.replace(i.month,i.strftime("%b"))
You can try this:
from datetime import datetime
dates = np.arange("2018-01-01", "2021-12-31", dtype="datetime64[D]")
result_dates = []
for date in dates.astype(datetime):
result_dates.append(date.strftime("%b-%d-%Y"))
But you will need to convert result dates as shown in the code
I feel compelled to elaborate on Silvio Mayolo's very relevant but ostensibly ignored comment above. Python stores a timestamp as structure (see How does Python store datetime internally? for more information) Hence, the DateTime does not as such have a 'format'. A format only becomes necessary when you want to print the date because you must first convert the timestamp to a string. Thus, you do NOT need to initialise any format. You only need to declare a format when the time comes to print the timestamp.
While you CAN store the date as a string in your dataframe index in a specific format, you CANNOT perform time related functions on it without first converting the string back to a time variable. ie current_time.hour will return an integer with the current hour if current_time is a datetime variable but will crash if it is a string formatted as a timestamp (such as "2023-01-15 17:23").
This is important to understand, because eventually you will need to manipulate the variables and need to understand whether you are working with a time or a string.
I've been trying to convert a column of a csv file (https://raw.githubusercontent.com/DNR07/CovidPredDatasets/main/covid_19_data.csv) to date time format using pandas.to_datetime() .
I've renamed the Observation date to just Date.
But when I use the aforementioned function I keep getting an error regarding the format of date time.
My exact code is:
c19_url="https://raw.githubusercontent.com/DNR07/CovidPredDatasets/main/covid_19_data.csv"
c19=requests.get(c19_url).content
df=pd.read_csv(io.StringIO(tr.decode('utf-8')))
df.rename(columns={'ObservationDate':'Date','Province/State':'Province_State',
'Country/Region':'Country_Region','Confirmed':'ConfirmedCases',
'Deaths':'Fatalities'},inplace=True)
df['Date'] = pd.to_datetime(df['Date'],format='%m/%d/%Y')
Now if you look at the CSV file, you can see that the format is
%m/%d/%Y, then why is the format in the error changing?
Error:
ValueError: time data '2020-01-22' does not match format '%m/%d/%Y' (match)
Where have I gone wong?
Should try:
df['Date'] = pd.to_datetime(df['Date'],format='%Y-%m-%d')
The issue actually was with the following line of code:
df=pd.read_csv(io.StringIO(tr.decode('utf-8')))
It works if you replace c19 with tr.
I made a silly mistake....
An example of a value in the Date column:
19/08/2017
Previously, I tried:
dividends['Date'] = pd.to_datetime(dividends['Date'])
to convert my column to have a datetime date type. However, when I then created charts out of this dataset (with 'Date' having a datetime date type), it always looked odd:
Having done a bit of trouble shooting online, I think the reason is because of the formatting of my datetime conversion. However, when I try to use this:
dividends['Date'] = pd.to_datetime(dividends['Date'],format='%d-%m-%y')
I get the error message
ValueError: time data '19/08/2017' does not match format '%d-%m-%y' (match)
Why is this, and how do I fix it? Cheers.
Use the following code:(note that I used Y in format):
dividends['Date'] = pd.to_datetime(dividends['Date'],format='%d-%m-%Y')
You could also use the following format:
'%d/%m/%Y'
I have a pandas dataframe with a column containing a date; the format of the original string is YYYY/DD/MM HH:MM:SS.
I am trying to convert the string into a datetime format, by using
df['Date']=pd.to_datetime(df['Data'], errors='coerce')
but plotting it I can see it doesn't recognize the correct format.
Can you help me to understand whether there is an option to give python the correct format to read the column?
I have seen the format tag for to_datetime function, but I can't use it correctly.
Thanks a lot for your help!
Try this:
df['Date'] = pd.to_datetime(df['Data'], format='%Y/%d/%m %H:%M:%S')
It looks like you're using a non-standard date format. It should be YYYY-MM-DD. Try formating with the strptime() method.
time.strptime('2016/15/07', '%Y/%d/%m')
If you need to get it to a string after that use time.strftime().
I am somewhat new to Python and have a seemingly simple question.
I have a python script that interacts with an API (RHN Satellite if you're curious). This API returns a date in the form of a string and it always trims leading 0's. For example, 6/1/13 or 10/9/12. I need to convert this string to a date and determine the day of the year it is.
Here is what I know:
today = datetime.datetime.now()
print today.strftime('%j')
...will return today's day of year (175). This works fine for a datetime object but I am having trouble converting the string given by the API to an actual date. If I use:
date = datetime.datetime.strptime(var, '%m/%d/$y')
I get error:
ValueError: time data '5/2/13' does not match format '%m/%d/$y'
I'm guessing because it's expecting leading 0's ? How do I get around this?
In the end, I am trying to subtract the variable date given from the current date but I can't do that until I convert the string.
Thanks for the help!
I think you just have a typo, use %y instead of $y:
date = datetime.datetime.strptime(var, '%m/%d/%y')
This code works for me, provided you change $y to %y in the format code.
Correct the $y to %y and I'd use format instead of strftime:
from datetime import datetime
print format(datetime.strptime('5/2/13', '%m/%d/%y'), '%j')