|
854 | 854 | "df.tail()" |
855 | 855 | ] |
856 | 856 | }, |
| 857 | + { |
| 858 | + "cell_type": "markdown", |
| 859 | + "metadata": {}, |
| 860 | + "source": [ |
| 861 | + "## Testing with Asserts\n", |
| 862 | + "* Use Asserts to Programmatically vs visually checking\n", |
| 863 | + "* If we drop or fill NaNs, we expect 0 missing values\n", |
| 864 | + "* We can write an assert statement to verify this\n", |
| 865 | + "* We can detect early warnings and errors\n", |
| 866 | + "* This gives us confidence that our code is running correctly\n", |
| 867 | + "\n", |
| 868 | + "### How Asserts work" |
| 869 | + ] |
| 870 | + }, |
| 871 | + { |
| 872 | + "cell_type": "code", |
| 873 | + "execution_count": 15, |
| 874 | + "metadata": {}, |
| 875 | + "outputs": [ |
| 876 | + { |
| 877 | + "ename": "AssertionError", |
| 878 | + "evalue": "", |
| 879 | + "output_type": "error", |
| 880 | + "traceback": [ |
| 881 | + "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m", |
| 882 | + "\u001b[1;31mAssertionError\u001b[0m Traceback (most recent call last)", |
| 883 | + "\u001b[1;32m<ipython-input-15-ca525b181386>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m\u001b[0m\n\u001b[0;32m 2\u001b[0m \u001b[1;32massert\u001b[0m \u001b[1;36m1\u001b[0m \u001b[1;33m==\u001b[0m \u001b[1;36m1\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m 3\u001b[0m \u001b[1;31m# If false, returns an error\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m----> 4\u001b[1;33m \u001b[1;32massert\u001b[0m \u001b[1;36m1\u001b[0m \u001b[1;33m==\u001b[0m \u001b[1;36m2\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m", |
| 884 | + "\u001b[1;31mAssertionError\u001b[0m: " |
| 885 | + ] |
| 886 | + } |
| 887 | + ], |
| 888 | + "source": [ |
| 889 | + "# If true, nothing is returned\n", |
| 890 | + "assert 1 == 1\n", |
| 891 | + "# If false, returns an error\n", |
| 892 | + "assert 1 == 2" |
| 893 | + ] |
| 894 | + }, |
857 | 895 | { |
858 | 896 | "cell_type": "code", |
859 | | - "execution_count": null, |
| 897 | + "execution_count": 16, |
| 898 | + "metadata": {}, |
| 899 | + "outputs": [ |
| 900 | + { |
| 901 | + "ename": "AssertionError", |
| 902 | + "evalue": "", |
| 903 | + "output_type": "error", |
| 904 | + "traceback": [ |
| 905 | + "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m", |
| 906 | + "\u001b[1;31mAssertionError\u001b[0m Traceback (most recent call last)", |
| 907 | + "\u001b[1;32m<ipython-input-16-0e3e9719daf4>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m\u001b[0m\n\u001b[0;32m 2\u001b[0m \u001b[1;31m# 1st .all() to return True or False for each column\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m 3\u001b[0m \u001b[1;31m# 2nd .alll() to return a single True or False\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m----> 4\u001b[1;33m \u001b[1;32massert\u001b[0m \u001b[0mdf\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mnotnull\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mall\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mall\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m", |
| 908 | + "\u001b[1;31mAssertionError\u001b[0m: " |
| 909 | + ] |
| 910 | + } |
| 911 | + ], |
| 912 | + "source": [ |
| 913 | + "# Note: Need to chain two .all(), \n", |
| 914 | + "# 1st .all() to return True or False for each column\n", |
| 915 | + "# 2nd .alll() to return a single True or False\n", |
| 916 | + "assert df.notnull().all().all()" |
| 917 | + ] |
| 918 | + }, |
| 919 | + { |
| 920 | + "cell_type": "code", |
| 921 | + "execution_count": 17, |
860 | 922 | "metadata": {}, |
861 | 923 | "outputs": [], |
| 924 | + "source": [ |
| 925 | + "assert (df['Age'] >=0).all().all()" |
| 926 | + ] |
| 927 | + }, |
| 928 | + { |
| 929 | + "cell_type": "markdown", |
| 930 | + "metadata": {}, |
862 | 931 | "source": [] |
863 | 932 | } |
864 | 933 | ], |
|
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