Questions tagged [pandas]
Pandas is a Python library for data manipulation and analysis, e.g. dataframes, multidimensional time series and cross-sectional datasets commonly found in statistics, experimental science results, econometrics, or finance. Pandas is one of the main data science libraries in Python.
pandas
288,144
questions
6
votes
2
answers
3k
views
pandas dataframe - change values based on column heading
I have a dataframe that looks like the following:
In [74]: data2
Out[74]:
a b c
2012-06-12 0 1 1
2012-06-13 1 1 0
2012-06-14 1 0 1
2012-06-15 1 0 1
2012-06-16 1 1 0
...
- 170
4
votes
3
answers
7k
views
Converting date/time in Pandas
I have stock ticker data in the following format:
40289.65972
40289.66319
40289.66667
and Excel is able to magically convert them to:
4/22/14 3:50 PM
4/22/14 3:55 PM
4/22/14 4:00 PM
via "Format ...
- 11.5k
10
votes
1
answer
6k
views
Converting data to missing in pandas
I have a DataFrame with a mix of 0's and other numbers. I would like to convert the 0's to missing.
For example, I am looking for the command that would convert
In [618]: a=DataFrame(data=[[1,2],[...
- 3,915
2
votes
1
answer
1k
views
Python pandas to partially collapse 2d matrix
I would like to partially "collapse" a DataFrame/matrix and keep the structure intact by just summing the condensed values. For example, I have this:
CHROM POS GENE DESC JOE ...
- 409
4
votes
1
answer
943
views
Add seconds to python datetime excluding weekends
I am trying to add seconds to python datetime excluding weekends using pandas. The code below works, but I would like to know if there is a simpler way to achieve this.
import datetime
from pandas ...
- 2,118
7
votes
2
answers
954
views
Joining a Pandas series with a hierarchical index back to the source DataFrame
I'm trying to wrap my brain around pandas data structures and trying to use them in anger a bit. I've figured out that groupby operations result in a pandas series object. But I can't quite figure out ...
- 60.5k
53
votes
4
answers
118k
views
Slice Pandas DataFrame by Row
I am working with survey data loaded from an h5-file as hdf = pandas.HDFStore('Survey.h5') through the pandas package. Within this DataFrame, all rows are the results of a single survey, whereas the ...
- 2,896
0
votes
1
answer
3k
views
Handle with European date format in python pandas
This question is somehow a continuation of this one. I've been able to correctly takes what I'm interested in a downloadable csv file as follow
import time
import urllib2
import csv
import sys
import ...
- 1,926
0
votes
1
answer
440
views
pandas: stacking DataFrames generated by apply
With a DataFrame, you can output Series when using DataFrame.apply to generate a new DataFrame with new columns
a b c
0 -0.119342 0.286710 0.266750
1 -1.514301 0.556106 -...
- 15k
428
votes
15
answers
809k
views
pandas: filter rows of DataFrame with operator chaining
Most operations in pandas can be accomplished with operator chaining (groupby, aggregate, apply, etc), but the only way I've found to filter rows is via normal bracket indexing
df_filtered = df[df['...
- 15k
150
votes
11
answers
200k
views
String concatenation of two pandas columns
I have a following DataFrame:
from pandas import *
df = DataFrame({'foo':['a','b','c'], 'bar':[1, 2, 3]})
It looks like this:
bar foo
0 1 a
1 2 b
2 3 c
Now I want to have ...
- 1,551
1
vote
2
answers
831
views
Pandas messing up dataframe
I'm creating a data frame in Pandas—
df_data = dict()
for x in data:
series = pandas.Series(x['value']['values'], index=x['value']['timestamps'])
df_data[x['_id']] = series
df = pandas....
- 6,287
5
votes
2
answers
11k
views
Pulling variable names when using pandas and statsmodels
I'm trying to access the names of variables from the results generated by statsmodels. I'll elaborate more after the example code.
import scikits.statsmodels.api as sm
import pandas as pd
data = sm....
- 1,802
0
votes
5
answers
2k
views
Pandas: date_range error [closed]
I'm getting an error using pandas date_range function. I've given the trace below, and can provide more context, but it seems like something I'm really going to have to dig into myself to solve.
So ...
- 1,257
17
votes
5
answers
27k
views
How to generate a list from a pandas DataFrame with the column name and column values?
I have a pandas dataframe object that looks like this:
one two three four five
0 1 2 3 4 5
1 1 1 1 1 1
I'd like to generate a list of lists objects where ...
- 7,933