The issue is probably that the formula function names are in French but Excel expects it to be stored/written in English. At least in the files written by XlsxWriter.
Try this instead:
shInfo.write('G3','=COUNTA(Analyse!C:C)-1',information)
shInfo.write('G5','=COUNTIF(Analyse!D:D,"To change")',information)
If you send me a small sample file saved using a French version of Excel I'll have a look and see if it is possible to set a flag in the files written by XlsxWriter to indicate the language of the formulas.
Update: The COUNTIF()
formula also needs to use the US style comma operator instead of ;
.
Update 2: Based on the sample file provided by @gatchan there is no language identifier in the file. The formula is translated to English and US style comma operator, by Excel, when it is saved .