I want to lag every column in a dataframe, by group. I have a frame like this: which looks like and I want it to look like this: This question manages the result for a single column, but I have an arbitrary number of columns, and I want to lag all of them. I can use groupby and apply, but
Tag: python
Error Installing Psycopg2 on MacOS 10.9.5
I’m trying to install Psycopg2 on my Macbook, but I am getting an error. I found a lot of the same questions on StackOverflow but no answer seems to work. I’m using: OS: MacOS 10.9.5 Python Version: 3.4.3 My error code is: Answer I ran pip install psycopg2-binary and it worked like charm More info…
How to install pyaudio on mac using Python 3?
I first tried: but I was told that Then I tried: Then I got: but I had installed portaudio Warning: portaudio-19.20140130 already installed So what can I do? Answer I’m assuming you are on a Mac. This is a simple issue to fix. First install Xcode. Then restart your computer. Afterwards run the commands …
Is it possible to run a pypy kernel in the Jupyter notebook?
I have always wondered if it were possible to run PyPy in the Jupyter notebook. I recently tried installing PyPy on my local machine, and it ran really well – 100X speedup in an agent-based simulation written in pure Python. However, I miss the interactivity in the Jupyter notebook. Is it possible to ma…
Write Large Pandas DataFrames to SQL Server database
I have 74 relatively large Pandas DataFrames (About 34,600 rows and 8 columns) that I am trying to insert into a SQL Server database as quickly as possible. After doing some research, I learned that the good ole pandas.to_sql function is not good for such large inserts into a SQL Server database, which was th…
How to read a Parquet file into Pandas DataFrame?
How to read a modestly sized Parquet data-set into an in-memory Pandas DataFrame without setting up a cluster computing infrastructure such as Hadoop or Spark? This is only a moderate amount of data that I would like to read in-memory with a simple Python script on a laptop. The data does not reside on HDFS. …
Drop frame while debugging?
I’d like to know if drop frame is available in PyCharm / Intellij with Python plugin. Here’s what the button looks like (it doesn’t show up on the debug toolbar so I assume it’s just not available for PyCharm) –> How to step one step back in IntelliJ? What I’m trying to …
TypeError argument must be an int or have a fileno() method
Seen here https://stackoverflow.com/search?q=TypeError+argument+must+be+an+int+or+have+a+fileno%28%29+method But just can’t quite find my answer. I am trying out a chat script Server side runs perfectly fine. But client Has run from cmd, not IDLE because of issues (read something about it relating to my…
pygame – How do I change a variable while it is being used?
I’m making a simple top-down game with moving and collision between player and walls, using pygame. I made my code so that when keys[pygame.K_LSHIFT] is True during the pygame.key.get_pressed at the state of the keyboard when it’s called, block_speed changes to 5 instead of 3. So it works and when…
Python: Pandas Dataframe how to multiply entire column with a scalar
How do I multiply each element of a given column of my dataframe with a scalar? (I have tried looking on SO, but cannot seem to find the right solution) Doing something like: gives me a warning: Note: If possible, I do not want to be iterating over the dataframe and do something like this…as I think any…