Skip to content

11.3/11.4 Reading a File & Iterating over lines in a file

11.3 Reading a File

  • To open this file, we would call the open function
  • The variable, fileref , now holds a reference to the file object returned by open
  • When we are finished with the file, we can close it by using the close method.
    • After the file is closed any further attempts to use fileref will result in an error.
>>>fileref = open("ccdata.txt", "r")
>>>
>>>fileref.close()
>>>

11.4 Iterating over lines in a file

  • Example file:

Pasted image 20230519154606.png

  • Example code for file
ccfile = open("ccdata.txt", "r")

for aline in ccfile:
    values = aline.split()
    print('In', values[0], 'the average temp. was', values[1], '°C and CO2 emmisions were', values[2], 'gigatons.')

ccfile.close()

Output
In 1850 the average temp. was -0.37 °C and CO2 emmisions were 2.24E-7 gigatons.
In 1860 the average temp. was -0.34 °C and CO2 emmisions were 3.94E-7 gigatons.
In 1870 the average temp. was -0.28 °C and CO2 emmisions were 6.6E-7 gigatons.
In 1880 the average temp. was -0.24 °C and CO2 emmisions were 1.1 gigatons.
In 1890 the average temp. was -0.42 °C and CO2 emmisions were 1.72 gigatons.
In 1900 the average temp. was -0.2 °C and CO2 emmisions were 2.38 gigatons.
In 1910 the average temp. was -0.49 °C and CO2 emmisions were 3.34 gigatons.
In 1920 the average temp. was -0.25 °C and CO2 emmisions were 4.01 gigatons.
In 1930 the average temp. was -0.14 °C and CO2 emmisions were 4.53 gigatons.
In 1940 the average temp. was 0.01 °C and CO2 emmisions were 5.5 gigatons.
In 1950 the average temp. was -0.17 °C and CO2 emmisions were 6.63 gigatons.
In 1960 the average temp. was -0.05 °C and CO2 emmisions were 10.5 gigatons.
In 1970 the average temp. was -0.03 °C and CO2 emmisions were 16 gigatons.
In 1980 the average temp. was 0.09 °C and CO2 emmisions were 20.3 gigatons.
In 1990 the average temp. was 0.3 °C and CO2 emmisions were 22.6 gigatons.
In 2000 the average temp. was 0.29 °C and CO2 emmisions were 24.9 gigatons.
In 2010 the average temp. was 0.56 °C and CO2 emmisions were 32.7 gigatons.
In 2019 the average temp. was 0.74 °C and CO2 emmisions were 33.3 gigatons.