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Trading Evolved – Errata and Updates

A book like Trading Evolved will without a doubt have errors. On top of errors, updates may also be needed as new versions of dependent software packages are released. I will keep a running log on this site of issues found, and suggested solutions. After this list grows long enough, I will update the book itself, and put a version number on it.

This article will be continuously updated.


Book Version 1.0

Version 1.0 of the book was released on August 8, 2019.

Unable to Install Zipline with Conda version 4.7.10

Conda version 4.7 seems to break some dependencies and may result in an inability to install Zipline using the syntax “conda install zipline -c quantopian”.

Workaround 1 – Downgrade Conda

Workaround 2 – Install using pip


Typo in “Patching the Framework”

On page 96 there’s a typo and the wrong file name is stated. This was the very last thing I did on the book before shipping it, as the issue that needed patching appeared at the last moment.

The file to be changed is “”, not “”.

Here is the complete, corrected version.

Zipline, like most software in Python world is not only free, but open source. You can see and edit all the code as you like, and one big advantage of this is that we can make changes and even fix bugs when needed. You may wonder why you would ever want to go and edit someone else’s code, but it can be very useful to have this possibility.

While writing this book, an interesting example of such a situation came up. One day, all the backtests suddenly stopped working, with an error message about failing to load benchmark data from some web address. As it turns out, there is a web call executed during backtests, where Zipline tries to pull data from an online source. This source, much like what happened to many other free data sources, suddenly stopped working without warning.

As of writing, this issue has not yet been addressed. But no worries, we can do it ourselves easily. We don’t actually need this benchmark data for anything that we will do in this book, and the easiest fix is to simply remove the web call and just return empty data.

My version of Zipline is 1.3, and if you’re working with the same version, you likely need to do this fix manually. It won’t take long.

First locate a file called, which should be in your Zipline installation folder. You can use the file system search tools to locate it. If you are on Windows, the path will probably be similar to this.


It’s always a good idea to keep a backup of the original code, so rename this file to keep a copy. Then make a new file, with the name, and put the following code in it before saving.

This code will simply return a data series from 1930 to 2030 with all zero values, which will effectively sidestep this web call issue, with no negative impact.

Addition to Patch

You may also need to bypass the cache in, in the same folder:


Zipline Installation: failed with current_repodata.json


Collecting package metadata (current_repodata.json): done
Solving environment: failed with current_repodata.json, will retry with next repodata source.


1) Update Conda to the latest version:

2) Install the free channel:

3) install Zipline:


Trouble Ingesting Quandl


“ValueError: Boolean array expected for the condition, not float64”


Downgrading Pandas to 0.18.1


Jupyter version 5.0.0 not starting


Downgrading “tornado” from 5.1.1 to 4.5.3


Trouble ingesting Quandl on Mac




  1. Steven Petersen

    Good new book so far. The following are no big deal but though I’d mention them.

    “If the volatility is exactly half in Microsoft, you would theoretically achieve the same risk level if you invest twice as much in Tesla.” should be “…twice as much AS in Tesla” ?

    “You can create both a folder and a new Python file through that dropdown on the right side, which you can see in Figure 5‑2.” should be “…a new Python FOLDER” ? There is an option to create a file so I got confused.

    • Yes, that first one is unfortunate. Leaving out ‘as’ gave the sentence the opposite meaning…

      But the second sentence seems fine to me, unless I’m still missing something. It’s not a Python folder, it’s a regular folder that you can create. Or ‘directory’ if you’re so inclined.

      So you can create folders in Jupyter, as well as Jupyter Notebook python files. Click the dropdown, and you’ll see.

  2. hi Andreas, thank you for the book. Great book. Hope to be even better at backtesting in time to come. By the way, the sp500 downloaded did not show sp500 values but it showed all the components within instead. My understanding from the book is 2 columns, 1 date and the other would be values under sp500. Am i right to say that? Thank you for taking the time to read this.

    • The file under “/Chapter 6 Pandas” contains a price series of the index, for use in the code in that chapter.

      The file under “/data/index_members/” contains the historical components.

      Yes, naming both files sp500.csv was unfortunate…

      Also, please write an Amazon review. These days far too many authors are paying for bulk reviews, having hundreds of reviews in the first week. I don’t resort to that, but I do resort to nagging on people to write reviews. 🙂

  3. Zipline Installation: failed with current_repodata.json

    Missing a dash led to another error. For step 2 it should be:

    conda config –set restore_free_channel true

    I’m loving the book so far. I’m no coder, but have found my interest in investing a useful tool to motivate me to solve problems and tinker.


    I had an issue trying to install the nb_conda package (pg.101) and while I didn’t save the error message it was something to do with nb_conda not being compatible with Python 3.5. Anyway I used the following command in the terminal from the link above to get it to install
    conda install -c conda-forge nb_conda

  5. Jupyter notebook not downloaded in my zip35 environment, open in jupyter greyed out, and cannot download notebook==6.0

    also can’t ingest quandl already downgraded pandas, or at least i think i did, just used

    conda install pandas=0.18.1

  6. which version of conda I should use to install zipline.

    First part of the message says
    “Workaround 1 – Downgrade Conda” , conda install conda=4.6.11

    The last part of the message says
    1) Update Conda to the latest version:

    What should I do?

  7. Just acquired “Trading Evolved” and want to thank you for your efforts in writing the book. I am finding it extremely useful in my quest to become proficient in using Python for financial analysis and equities trading.

    In the course of following along with the book in Jupyter Notebook I encountered an error in running “first Zipline backtest” as follows:

    ValueError: SQLite file ‘C:\\Users\\r1100/.zipline\\data\\quandl\\2019-08-21T20;57;11.306361\\assets-6.sqlite’ doesn’t exist

    So my question is what is this file and what is required to bring it into existence? Thank you.

    • That sounds like an error during bundle ingest. If you interrupt the ingest process, or if it for any reason fails, this error shows up. Try ingesting it again.

      Also, the Quandl bundle is very limited and I would very much recommend making your own bundle, for your own data, as explained in the later chapters in the book.

    • I don’t recall doing anything that would cause the ingest process to be interrupted. I will certainly try the ingest process again but with the verbose mode on (note I mostly use iPython) to get a better idea of what is going on should the error repeat. I think I will start making my own bundles – I prefer having more control over the overall process.

    • Oh, and be sure to start the kernel in the notebook after ingesting. In case you had the notebook running while doing the ingest, you’ll need to restart the kernel.

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