Python for Entrepreneurs Transcripts
Chapter: Appendix: Python language concepts
Lecture: Concept: Named tuples
0:01 In the previous section we discussed tuples, and how they are useful.
0:04 Sometimes these anonymous tuples that we discussed are exactly what you need,
0:08 but oftentimes, it's very unclear what values are stored in them,
0:12 especially as you evolve the software over time.
0:15 On the second line here, we have "m", a measurement we are defining
0:18 this time it's something called a named tuple
0:21 and just looking at that definition there on what we are instantiating
0:24 the measurement, it's not entirely clear the first value is the temperature,
0:28 the second value is the latitude, this third value is a longitude, and so on.
0:32 And we can't access it using code that would treat it like a plain tuple,
0:36 here we say the temperature is "m" of zero
0:39 which is not clear at all unless you deeply understand this
0:42 and you don't change this code, but because we define this as a named tuple,
0:47 here at the top we define the type by saying
0:50 measurement is a collections.namedtuple,
0:53 and it's going to be called a measurement,
0:55 for error purposes and printing purposes and so on,
0:58 and then you define a string which contains all the names for the values.
1:02 So over here you are going to say this type of tuple temperature's first, then latitude,
1:06 then longitude, then quality, and what that lets us do is access those values by name.
1:11 So instead of saying "m" of zero temperature,
1:13 we say m.temp is the temperature, and the quality is m.quality.
1:16 Named tuples make it much easier to consume these results
1:20 if you are going to start processing them
1:23 and sharing them across methods and things like that.
1:25 Additionally, when you print out a named tuple it actually prints a friendlier version
1:29 here at the bottom you see measurement of temperature, latitude, longitude, and quality.
1:33 So most of the time if you are thinking about creating a tuple,
1:36 chances are you should make a named tuple.
1:39 There is a very small performance overhead but it's generally worth it.