Hi guys,
I've the following dataframe df:

    IID        PC1          PC2         PC3          PC4         PC5         PC6          PC7          PC8          PC9
    1 11:00223.CEL 0.00229647 -0.000423608 0.001480000  1.02983e-03  0.00418171 -0.00550339  0.003826840  0.002836460 -0.001210240
    2      9399.CEL 0.00213518 -0.000734612 0.000965396  9.84589e-04 -0.00135706  0.00396061  0.006356090  0.000639752 -0.000220536
    3     shckanc.CEL 0.00225502 -0.000971542 0.001553290  2.13150e-03 -0.00277924  0.00291143  0.007620090 -0.002271640 -0.003364920
    4   787323A1.CEL 0.00292725 -0.000399576 0.001340910  6.99230e-06 -0.00299630 -0.00769350 -0.007620050  0.002889230  0.005459370
    5     90w3jc.CEL 0.00228869 -0.000201784 0.001291800  8.68436e-04 -0.00194812 -0.00554044 -0.006723900  0.001160370  0.005532150
    6    olsj909.CEL 0.00224916 -0.000530798 0.000677401 -1.13087e-04 -0.00132783 -0.00814353 -0.000705561  0.000352494  0.000671816

Considering the first column IID, I need to extract all the string before the dot, excluding .CEL
Just an example: for the first row, I need to extract `11:00223`, for the second row `9399` and so on...

I tried using the library `stringr` and then the following command line:

    str_extract(df$IID, "[[:digit:]]+")

but `[[:digit:]]+` extracts only number before the dot, while I need all the string before the dot, included letters of the alphabet.

Any idea about how to extract all the string before the dot?

Thank you!
    gsub("\\..*", "", string)
