Join Michele Vallisneri for an in-depth discussion in this video Solution, part of Introduction to Data Analysis with Python.
- Let's look at my solution.…In the IPython notebook interface, let's select…the 0707 challenge begin exercise file.…I'm going to use the code that we developed…in this chapter.…So let's select cell, run all.…Here we are.…First, we sum over all years to get totals.…After grouping by sex and name,…we select the number column alone…and take the sum.…Next, we will unstack the totals by making the sex…into separate columns.…
Let's have a look.…Just as we need, we can then sum the two columns…together by applying SUM along the column axis.…Let's have a look.…Excellent.…We can then compute the ratio by dividing…the column F by the column M.…And I'm going to assign the result to the variable ratio.…So I move to the beginning of the line,…type in, "ratio=".…
Let's have a look.…The ratio turns out not a number for the names…that are not used for both sexes.…That's normal.…Next, we can compute a boolean mask that selects…the unisex names.…For that, we're going to select the names…for which the ratio is greater than .25 but less than four.…
- Writing and running Python in iPython
- Using Python lists and dictionaries
- Creating NumPy arrays
- Indexing and slicing in NumPy
- Downloading and parsing data files into NumPy and Pandas
- Using multilevel series in Pandas
- Aggregating data in Pandas
Skill Level Intermediate
Q: The course shows how to download files from FTP and web servers using Python 3.X. How do I do the same thing with Python 2.7?
A: First import urllib, then use urllib.urlretrieve(URL,filename). For instance, to download the stations.txt files used in the chapter 5 video “Downloading and parsing data files,” you’d do urllib.urlretrieve(‘ftp://ftp.ncdc.noaa.gov/pub/data/ghcn/daily/ghcnd-stations.txt','stations.txt').
1. Installation and Setup
2. Refresher: Data Containers in Python
3. Word Anagrams in Python
4. Introduction to NumPy
5. Weather Data with NumPy
6. Introduction to Pandas
7. Baby Names with Pandas
Next steps1m 36s
- Mark as unwatched
- Mark all as unwatched
Are you sure you want to mark all the videos in this course as unwatched?
This will not affect your course history, your reports, or your certificates of completion for this course.Cancel
Take notes with your new membership!
Type in the entry box, then click Enter to save your note.
1:30Press on any video thumbnail to jump immediately to the timecode shown.
Notes are saved with you account but can also be exported as plain text, MS Word, PDF, Google Doc, or Evernote.