parsing.md

Parsing data from text

Most text files contain both text and numbers. Extracting these data fields from a file and storing them in reasonably structured variables is called parsing. To parse files, we need methods of strings, lists and type conversions.

Exercise 1

Insert the following pieces into the code, so that all commands are executed correctly: age, int(age), name, str(born), 2000

name = 'Emily Smith'
born = _____
____ = '15'

text = ____ + ' was born in the year ' + _____ + '.'
year = born + _____
text
year

Exercise 2

The following program collects names in a list that occur at least 10000 times. Unfortunately, the program contains four errors. Find and fix these.

frequent = []

for line in open('names/yob2015.txt'):
    columns = line.strip().split(',')
    name = colums[1]
    anzahl = int(columns[3])
    if anzahl >= 10000
        frequent.append(name)

print(frequent)

Exercise 3

Write a program that calculates the total number of babys for the year 2015 and writes it to the screen. Compare that number with the year 1915.

Exercise 4

Write a program that finds the three most frequent names for boys and girls in a given year and writes them to the screen.

Hint: The three most frequent names are on top of the list.

Exercise 5

Write a program that calculates the percentage of the 10 most frequent names for the year 2015 and writes it to the screen.