I have managed to use Python with the speedtest-cli package to run a speedtest of my Internet speed. I run this every 15 min and append the results to a .csv file I call "speedtest.csv". I then have this .csv file emailed to me every 12 hours, which is a lot of data.
I am only interested in keeping the rows of data that return less than 13mbps Download speed. Using the following code, I am able to filter for this data and append it to a second .csv file I call speedtestfilteronly.csv.
import pandas as pd
df = pd.read_csv('c:\speedtest.csv', header=0)
df = df[df['Download'].map(lambda x: x < 13000000.0,)]
df.to_csv('c:\speedtestfilteronly.csv', mode='a', header=False)
The problem now is it appends all the rows that match my filter criteria every time I run this code. So if I run this code 4 times, I receive the same 4 sets of appended data in the "speedtestfilteronly.csv" file.
I am looking to only append unlike rows from speedtest.csv to speedtestfilteronly.csv.
How can I achieve this?
I have got the following code to work, except the only thing it is not doing is filtering the results to < 13000000.0 mb/s: Any other ideas?
import pandas as pd
df = pd.read_csv('c:\speedtest.csv', header=0)
df = df[df['Download'].map(lambda x: x < 13000000.0,)]
history_df = pd.read_csv('c:\speedtest.csv')
master_df = pd.concat([history_df, df], axis=0)
new_master_df = master_df.drop_duplicates(keep="first")
new_master_df.to_csv('c:\emailspeedtest.csv', header=None, index=False)
There's a few different way you could approach this, one would be to read in your filtered dataset, append the new one in memory and then drop duplicates like this:
import pandas as pd
df = pd.read_csv('c:\speedtest.csv', header=0)
df = df[df['Download'].map(lambda x: x < 13000000.0,)]
history_df = pd.read_csv('c:\speedtestfilteronly.csv', header=None)
master_df = pd.concat([history_df, df], axis=0)
new_master_df = master_df.drop_duplicates(keep="first")
new_master_df.to_csv('c:\speedtestfilteronly.csv', header=None, index=False)
Related
I have this code which appends a column of a csv file as a row to another csv file:
def append_pandas(s,d):
import pandas as pd
df = pd.read_csv(s, sep=';', header=None)
df_t = df.T
df_t.iloc[0:1, 0:1] = 'Time Point'
df_t.at[1, 0] = 1
df_t.columns = df_t.iloc[0]
df_new = df_t.drop(0)
pdb = pd.read_csv(d, sep=';')
newpd = pdb.append(df_new)
from pandas import DataFrame
newpd.to_csv(d, sep=';')
The result is supposed to look like this:
Instead, every time the row is appended, there is an extra "Unnamed" column appearing on the left:
Do you know how to fix that?..
Please, help :(
My csv documents from which I select a column look like this:
You have to add index=False to your to_csv() method
The code below only exports the last table on the page to excel, but when I run the print function, it will print all of them. Is there an issue with my code causing not to export all data to excel?
I've also tried exporting as .csv file with no luck.
import pandas as pd
url = 'https://www.vegasinsider.com/college-football/matchups/'
dfs = pd.read_html(url)
for df in dfs:
if len(df.columns) > 1:
df.to_excel(r'VegasInsiderCFB.xlsx', index = False)
#print(df)
Your problem is that each time df.to_excel is called, you are overwriting the file, so only the last df will be left. What you need to do is use a writer and specify a sheet name for each separate df e.g:
url = 'https://www.vegasinsider.com/college-football/matchups/'
writer = pd.ExcelWriter('VegasInsiderCFB.xlsx', engine='xlsxwriter')
dfs = pd.read_html(url)
counter = 0
for df in dfs:
if len(df.columns) > 4:
counter += 1
df.to_excel(writer, sheet_name = f"sheet_{counter}", index = False)
writer.save()
You might need pip install xlsxwriter xlwt to make it work.
Exporting to a csv will never work, since a csv is a single data table (like a single sheet in excel), so in that case you would need to use a new csv for each df.
As pointed out in the comments, it would be possible to write the data onto a single sheet without changing the dfs, but it is likely much better to merge them:
import pandas as pd
import numpy as np
url = 'https://www.vegasinsider.com/college-football/matchups/'
dfs = pd.read_html(url)
dfs = [df for df in dfs if len(df.columns) > 4]
columns = ["gameid","game time", "team"] + list(dfs[0].iloc[1])[1:]
N = len(dfs)
values = np.empty((2*N,len(columns)),dtype=np.object)
for i,df in enumerate(dfs):
time = df.iloc[0,0].replace(" Game Time","")
values[2*i:2*i+2,2:] = df.iloc[2:,:]
values[2*i:2*i+2,:2] = np.array([[i,time],[i,time]])
newdf = pd.DataFrame(values,columns = columns)
newdf.to_excel("output.xlsx",index = False)
I used a numpy.array of object type to be able to copy a submatrix from the original dataframes easily into their intended place. I also needed to create a gameid, that connects the games across rows. It should be now trivial to rewrite this so you loop through a list of urls and write these to separate sheets.
Excel limits the columns of any csv file around 3000. I am trying to write 125,000 columns in the following format:
O1
MA1
MI1
C1
V1
...
O125000
MA125000
MI125000
C125000
V125000
import pandas as pd
def formatting(i):
return tuple(map(lambda x: x+str(i), ("O", "MA", "MI", "C", "V")))
l = []
for i in range(1, 125001):
l.extend(formatting(i))
f = pd.read_csv('file.csv')
f.columns = l
f.to_csv('new_file.csv')
I tried coding this script but its too slow and inconsistent in the fact that its prone to errors. However, you can get the idea of what I am trying to do from this script.
The current script I use to generate a csv(that contains 2 rows and 125,000+ columns) is the following:
import pandas as pd
import glob
allfiles = glob.glob('*.csv')
index = 0
def testing(file):
#file = file.loc[:,'Open':'Volume']
file = file.values.reshape(1, -1)
return file
for _fileT in allfiles:
nFile = pd.read_csv(_fileT, header=0, usecols=range(1,6))
fFile = testing(nFile)
df = pd.DataFrame(fFile)
new_df = df.iloc[:125279]
new_df = new_df.shift(1, axis=1)
new_df.to_csv('HeadCSV/FinalCSV.csv', mode='a', index=False, header=0)
This script reads two csv files in the directory, and aggregates them into one file however how can I make sure that it prints the header mentioned above and labels the two rows it prints out?
Id basically like to combine these two scripts in the most logical way possible.
the idea is to write the header, then get all the data from the files into the dataframe, then do the row indexing as mentioned, and finally throw it all into a CSV
I have a strange issue on pandas.read_csv function. I exported my dataframe into a csv, but when I re-imported the same csv, the data that has been imported back does not work when I try to merge(The merge shows all the data on the left and none that I have tried to merge it with). If I use the original data before it was exported to the csv, it works completely fine.(The merge was perfect).
df = df.values_list('id','teacher_id','uniquecount','nonuniquecount','msgcount','ordercount','date','updated','timestamp', flat=False)
#inserting the collected data into a dateframe for manipulation
df = pd.DataFrame(list(df))
#giving the dataframe column names
df.columns = ['id','teacher_id','uniquecount','nonuniquecount','msgcount','ordercount','date','updated','timestamp']
df = df[['id','teacher_id','uniquecount','nonuniquecount','msgcount','ordercount','date']]
#rename required columns
df.rename(columns={'uniquecount':'Unique Views','nonuniquecount':'Views','msgcount':'Messages','ordercount':'Orders'}, inplace=True)
print df
print df.dtypes
# exporting df out to a csv
# df.to_csv('test.csv', header=True)
# importing the df back from a csv
df = pd.read_csv('test.csv', index_col=0)
print df
print df.dtypes
#insert dates
numdays = 14
base = datetime.datetime.today().date()
date_list = [base - datetime.timedelta(days=x) for x in range(0, numdays)]
dates = pd.DataFrame(date_list)
dates.columns = ['date']
#merge the complete dates with the dateframe
df = pd.merge(dates ,df , on=['date'] , how='left')
# print df
I have checked and compared that the dataframes look exactly the same before export and after importing from the csv.(I printed the output twice, once before export and one after) I have also checked and the datetypes are all the same.
I need to export the csv to work with an external environment because I cant attach my local database.
attached a copy of the cmdline print which shows that both dataframes are exactly similar
attached below is a sample of my exported csv
,id,teacher_id,Unique Views,Views,Messages,Orders,date
0,47,31,1,6,0,0,2017-05-09
1,56,31,1,9,0,0,2017-05-10
2,67,31,2,11,0,0,2017-05-14
3,71,31,3,15,0,0,2017-05-15
4,79,31,3,17,0,0,2017-06-12
5,83,31,3,18,0,1,2017-06-18
Does anyone have any idea on this strange issue?
Before calling merge, try converting both dates using to_datetime first as referred in answer here
df.date = pd.to_datetime(df.date)
dates.date = pd.to_datetime(dates.date)
#merge the complete dates with the dateframe
df = pd.merge(dates ,df , on=['date'] , how='left')
For my master thesis, I need to calculate expected returns for x number of stocks on a given event date. I have written the following code, which does what I intends (match Fama & French factors with a sample of event dates). However, when I try to export it to excel I can't seem to get the correct output. I.e. it doesn't contain column headings such as Dates, names of fama & french factors and the corresponding rows.
Does anybody have a workaround for this? Any improvements are gladly appreciated. Here are my code:
import pandas as pd
# Data import
ff_five = pd.read_excel('C:/Users/MBV/Desktop/cmon.xlsx',
infer_datetime_format=True)
df = pd.read_csv('C:/Users/MBV/Desktop/4.csv', parse_dates=True,
infer_datetime_format=True)
# Converting dates to datetime
df['Date'] = pd.to_datetime(df['Date'], infer_datetime_format=True)
# Creating an empty placeholder
end_date = []
# Iterating over the event dates, creating a start and end date 60 months
apart
for index, row in df.iterrows():
end_da = row['Date']-pd.DateOffset(months=60)
end_date.append(end_da)
end_date_df = pd.DataFrame(data=end_date)
m = pd.merge(end_date_df,df,left_index=True,right_index=True)
m.columns = ['Start','End']
ff_factors = []
for index, row in m.iterrows():
ff_five['Date'] = pd.to_datetime(ff_five['Date'])
time_range= (ff_five['Date'] > row['Start']) & (ff_five['Date'] <=
row['End'])
df = ff_five.loc[time_range]
ff_factors.append(df)
EDIT:
Here are my attempt at getting the data from python to excel.
ff_factors_df = pd.DataFrame(data=ff_factors)
# Create a Pandas Excel writer using XlsxWriter as the engine.
writer = pd.ExcelWriter('estimation_data.xlsx', engine='xlsxwriter')
# Convert the dataframe to an XlsxWriter Excel object.
ff_factors_df.to_csv(writer, sheet_name='Sheet1')
# Close the Pandas Excel writer and output the Excel file.
writer.save()
To output a dataframe to csv or excel should be able to be done with
ff_five.to_excel('Filename.xls')
Change excel to csv if you want it to a csv.
Ok I tried to interpret what you were trying to do without it being very clear. But if I was interpreting it correctly you are trying to create some addition columns based on other data. Instead of creating separate lists you could possibly just put them in as new columns and then just output the columns you want potentially. Something like this maybe (had to make some assumptions and create some fake data to see if this is on the right track):
import pandas as pd
ff_five = pd.DataFrame()
ff_five['Date'] = ["2012-11-01", "2012-11-30"]
df = pd.DataFrame()
df['Date'] = ["2012-12-01", "2012-12-30"]
df['Date'] = pd.to_datetime(df['Date'])
df['End'] = df['Date'] - pd.DateOffset(months=60)
df.columns = ['Start', 'End']
ff_five['Date'] = pd.to_datetime(ff_five['Date'])
df['ff_factor'] = (ff_five['Date'] > df['Start']) & (ff_five['Date'] <= df['End'])
df.to_excel('estimation_data.xlsx', sheet_name='Sheet1')