Hands On¶

Questions¶

• What uses do the different brackets have: [], (), {}
• Give a possible use for each of the following container: Dictionary, Set, Tuple
• What is a keyword-argument? Where in the list of arguments do keyword-arguments belong?
• You can type my_func? to geht help on my_func. If you wrote my_func, what do you need to do to get a useful help-text?
• When do you use for-loops, when while? Give an example of both loops.
• What is the difference between break, continue and return?
• After reading the content of a file, how do you restart reading from the first line?
• Why is it a good idea to use a contect-manager when reading files?
• What is the difference between a string defined with "String" and r"String"
• What does sys.argv[0] return?

Tasks¶

• Improve your refugee code
  • store the three data variables (years, countries, refugees) into a sensible data structure.
  • adapt the plot function such that it accepts arbitrary keyword-arguemnts and passes unknown arguments on to the plot function.
  • add a command-line interface using argparse

• In the data directory you find gdp-europe.csv. This file contains the GDP per capita for the same countries as refugees.
  • Add the data to your script.
  • Calculate and plot the refugee number relative to the GDP.
  • Create a scatter plot with all countries.

• Implement a library, that provides basic formulas from Macro- or Microeconomics. (You probably know better what you could implement then me.) Each formula should be implemented as a separat function taking the relevant parameters as arguments.

• Write a simple command-line interface that provides access to the functions in your library from above. (You can either expect the relevant input on the command line or ask for it interactively.

• Have a look at https://docs.python.org/3.6/library/turtle.html. Implement something nice with it :-)

Brute Force¶

Assume you find the following password comparison in the source code.
from hashlib import md5 ... if md5(pin.encode()).digest() == hash: ...

In addition you know that the pin is 1 to 4 digits long.

md5 is a bad hashing algorithm for passwords. So it should be straight forward to brute-force the password. (try all possible combinations)

Once this works adapt the code to use argon2 instead of md5. You will still be able to brute-force such a short pin. It should however take significantly longer.

Small Problems¶

Download the file exercises.zip and look at the .py files. Choose one ore more of the problems and solve them.