corrected challenge to provide meaningul error

wrightaprilm · NPalopoli · web-flow · commit 4738cb419fb3 · 2018-11-30T10:23:07.000+01:00
Co-Authored-By: NPalopoli &lt;nicopalo@gmail.com&gt;
diff --git a/_extras/extra_challenges.md b/_extras/extra_challenges.md
@@ -30,7 +30,7 @@ A collection of challenges that have been either removed from or not (yet) added
 > {: .language-python}
 >
 > What happens if there is no data for a year in a sequence? For example,
-> imagine we used `1976` as the start year in `range`
+> imagine we used `1976` as the year in `surveys_df[surveys_df.year == year]`
 >
 > > ## Solution
 > > An empty file with only the headers  

Original file line number	Diff line number	Diff line change
`@@ -30,7 +30,7 @@ A collection of challenges that have been either removed from or not (yet) added`
`30`	`30`	`> {: .language-python}`
`31`	`31`	`>`
`32`	`32`	`> What happens if there is no data for a year in a sequence? For example,`
`33`		-> imagine we used `1976` as the start year in `range`
	`33`	+> imagine we used `1976` as the year in `surveys_df[surveys_df.year == year]`
`34`	`34`	`>`
`35`	`35`	`> > ## Solution`
`36`	`36`	`> > An empty file with only the headers`