Pandas is a Python data analysis library.
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Load recurring (but not strictly identical) sets of Key, Values into a DataFrame from text files
I am reading text files that contain data from observations. The format is not Fixed Width or Delimited, so I built a generator ...
4
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1answer
56 views
Using Pandas to parse adwords export
I did this exercise yesterday mostly as practice, but it has some utility as well in day to day. I was basically attempting to take a string that looked like the following:
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1answer
52 views
Slicing time spans into calendar months
I have apparently correct code that still runs for weeks on my data (tens of millions of rows). I show the entire code for reference (and maybe other gains to be made), but the key operation is in the ...
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1answer
32 views
Multi-linear regression with trivial model refinement algorithms
I wrote this code for an assignment. It was originally meant to be written in Maple, but got very frustrated with some of Maple's idiosyncrasies that I decided to play around with Pandas instead. This ...
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2answers
64 views
Generating a PANDAS DataFrame of simulated coin tosses
It's taking my machine quite a long time to execute 1 billion (1st loop x 10, 2nd loop x 1000, 3rd loop x 100,000) instructions. Suggestions for performance enhancements? Sources of potential concern: ...
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1answer
49 views
Random Forest Code Optimization
I am new to Python. I have built a model with randomforest in python. But I think my code is not optimized. Please look into my code and suggest if I have deviated from best practices.
Overview about ...
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2answers
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Project Euler #19: Counting Sundays in the 20th century using Pandas
Project Euler #19 asks:
How many Sundays fell on the first of the month during the twentieth century (1 Jan 1901 to 31 Dec 2000)?
I'm hoping I wasn't too off course from the spirit of the ...
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1answer
55 views
Operating multiple columns of one pandas DataFrame using data from another
I have a DataFrame of data from a survey that was repeated over several years, asking people about their income and how much money they had in savings. For simplicity, let's pretend it looks like ...
2
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1answer
58 views
Creating a time-course dependent, correlation-based directed graph with Networkx
I have a correlation matrix containing 4 time points, each with multiple samples. Each sample is identified with a time point with its name. What I am trying to accomplish here is to create a directed ...
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1answer
32 views
Reading groups of files and concatenating them
I have made some adjustments to some code that you can see on this thread:
Read daily files and concatenate them
I would like to make some further refinements and make sure I am on the right track ...
3
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2answers
114 views
Read daily files and concatenate them
Edit - here is my modified code: http://jsfiddle.net/#&togetherjs=GzytydCsRh
Can someone take a look and give me some feedback? It seems a bit long still but that is the first time I used ...
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1answer
157 views
A big “Game of Life”
Our quest: Create a big simulation for Conway's Game of Life, and record the entire simulation history.
Current Approach: Cython is used for an iterate method. The ...
5
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1answer
473 views
A custom Pandas dataframe to_string method
Oftentimes I find myself converting pandas.DataFrame objects to lists of formatted row strings, so I can print the rows into, e.g. a ...
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1answer
39 views
Reading and processing a file using Pandas
I am trying to read a file using pandas and then process it. For opening the file I use the following function:
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375 views
Tkinter GUI for making very simple edits to pandas DataFrames
It is part of a separate application that allows users to interact very loosely with different databases and check for possible errors and make corrections.
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45 views
Outputting scatter plots
I have written a python function that outputs scatter plots using Matplotlib after processing the data a little. It works but it's painfully slow. I was wondering if anybody had any suggestions as to ...
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4answers
680 views
Chi Square Independence Test for Two Pandas DF columns
I want to calculate the scipy.stats.chi2_contingency() for two columns of a pandas DataFrame. The data is categorical, like this:
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3
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1answer
205 views
Imputing values with non-negative matrix factorization
X is a DataFrame w/ about 90% missing values and around 10% actual values. My goal is to use nmf in a successive imputation loop to predict the actual values I have ...
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1answer
63 views
Querying houses similar to a given house
I was given this task as an interview coding challenge and was wondering If the code is well structured and follows python guidelines. I chose to sort the houses based on a similarity metric and then ...
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3answers
221 views
Rating tennis players in a database, taking days to run
I have this project in data analysis for creating a ranking of tennis players. Currently, it takes more than 6 days to run on my computer.
Can you review the code and see where's the problem?
...
3
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2answers
380 views
Extracting contents of dictionary contained in Pandas dataframe to make new dataframe columns
I created a Pandas dataframe from a MongoDB query.
c = db.runs.find().limit(limit)
df = pd.DataFrame(list(c))
Right now one column of the dataframe corresponds ...
3
votes
1answer
98 views
Data cleansing and formatting script
This is a script that creates a base dataframe from a sqlite database, adds data to it (also from SQLite), cleanse it and formats it all to an Excel file. I feel like it is incredibly verbose and my ...
3
votes
1answer
116 views
Fetching, processing, and storing Mixpanel analytics data to SQLite
I'm a self-taught Python programmer and I never really learned the fundamentals of programming, so I want to see how to improve upon this script and make it adhere to best practices.
The script has ...
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vote
1answer
525 views
Split excel file with multiple sheets, manipulate the data and create final out file
I have an excel file with 20+ separate sheets containing tables of data. My script iterates through each sheet, manipulates the data into the format I want it and then saves it to a final output file. ...
2
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1answer
36 views
Excel Laboratory Data Entry from Python 2.7
I've written a script to automate the entry of laboratory instrument data into an Excel spreadsheet using pandas and win32com.
I've got the script functioning correctly, but it is painfully slow. In ...
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1answer
176 views
Reading an Excel file and comparing the amino acid sequence of each data pair
Since I am fairly new to Python I was wondering whether anyone can help me by making the code more efficient. I know the output stinks; I will be using Pandas to make this a little nicer.
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5
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1answer
1k views
Efficient Pandas to MySQL “UPDATE… WHERE”
I have a pandas DataFrame and a (MySQL) database with the same columns. The database is not managed by me.
I want to update the values in the database in an "UPDATE... WHERE" style, updating only ...
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1answer
38 views
Identifying surface events happening at specific time intervals
Here is some code I wrote to surface Mint.com transactions that occur at monthly intervals, in order to identify subscriptions I may be paying for without realizing it.
I'd like to have some friends ...
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1answer
262 views
Simple k-means implemention using Python3 and Pandas
Is there anything I can improve? The distance function is Pearson correlation.
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1answer
103 views
SQL GROUPING SETS in Python using Pandas
The code below is intended to provide SQL's GROUPING SETS functionality in Python with the aid of Pandas.
Background on SQL GROUPING SETS
There are at least two advantages to doing this in Python:
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6
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2answers
86 views
Speed up script that calculates distribution of every character from user input
I have a data set with close to 6 million rows of user input. Specifically, users were supposed to type in their email addresses, but because there was not pattern validation put in place we have a ...
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203 views
Parsing URLs in Pandas DataFrame
My client needs their Google AdWords destination URL query parsed and the values spell checked to eliminate any typos ("use" instead of "us", etc).
I'm pulling the data using the AdWords API and ...
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2answers
356 views
Matplotlib-venn and keeping lists of the entries
Having come upon the wonderful little module of matplotlib-venn I've used it for a bit, I'm wondering if there's a nicer way of doing things than what I have done so far. I know that you can use the ...
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212 views
Speed up Pandas DataFrame expansion to include time-lagged information about events
Using pandas and Python 3, information about a simple timeseries data set is being processed. Within the span of .5 seconds, 3 names are being said. We record the onset of each utterance, the length ...
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165 views
Monte Carlo estimation of the Hypergeometric Function
I am trying to implement the algorithm described in the paper Statistical Test for the Comparison of Samples from Mutational Spectra (Adams & Skopek, 1986) DOI: 10.1016/0022-2836(87)90669-3:
$$p ...
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212 views
Speeding up filtering function in Pandas
I have a CSV file with 400 000 rows and the following headers:
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275 views
Speed up projection of a bipartitie network for a big file using NetworkX and Pandas
I have a pretty big file (3 million lines) with each line being a person-to-event relationship. Ultimate, I want to project this bipartite network onto a single-mode, weighted, network, and write it ...
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1answer
930 views
Simplifying Python Pandas code for selecting co-occurrences in a window of time
I am a beginner at programming. I was able to build the thing below, which achieves what I want with a small dataset. With larger datasets, my RAM gets swamped bringing the computer to a halt (2014 ...
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vote
1answer
932 views
Parse Bloomberg Excel/CSV with Pandas DataFrame
I retrieved Bloomberg data using the Excel API. In the typical fashion, the first row contains tickers in every fourth column, and the second row has the labels Date, PX_LAST, [Empty Column], Date, ...
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1answer
5k views
Working with pandas dataframes for stock backtesting exercise
I'm attempting to apply a long set of conditions and operations onto a pandas dataframe (see the dataframe below with VTI, upper, lower, etc). I attempted to use apply, but I was having a lot of ...
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73 views
Generate features for future ML analysis of asset returns
I have built the following code to download stock data from Yahoo Finance. The plan is to then use the built-in pandas functions to calculate metrics from this data ...
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1answer
789 views
Better implementation of Excel's SUMIFS using pandas, the Python Data Analysis Library
I've implemented Excel's SUMIFS function in Pandas using the following code. Is there a better—more Pythonic—implementation?
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1answer
4k views
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140 views
Long expression to sum data in a multi-dimensional model
I am porting a linear optimization model for power plants from GAMS to Pyomo. Models in both frameworks are a collection of sets (both elementary or tuple sets), parameters (fixed values, defined over ...
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545 views
Inventory simulation using Pandas DataFrame
I've been learning Python like for a year and started learning a little about pandas DataFrame. I made this little program to practice all the concepts and would ...
