R: Extract list columns based on column names and patterns -

i have list (here sample data)

my_list <- list(structure(list(sample = c(2l, 6l), data1 = c(56l, 78l),      data2 = c(59l, 27l), data3 = c(90l, 28l), data1namet = structure(c(1l,      1l), .label = "sam1", class = "factor"), data2namab = structure(c(1l,      1l), .label = "test2", class = "factor"), dataame = structure(c(1l,      1l), .label = "ex3", class = "factor"), ma = c("jay", "jay"     )), .names = c("sample", "data1", "data2", "data3", "data1namet",  "data2namab", "dataame", "ma"), row.names = c(na, -2l), class = "data.frame"),      structure(list(sample = c(12l, 13l, 17l), data1 = c(56l,      78l, 3l), data2 = c(59l, 27l, 2l), datest = structure(c(1l,      1l, 1l), .label = "exa9", class = "factor"), dattestr = structure(c(1l,      1l, 1l), .label = "cz1", class = "factor"), add = c(2, 2,      2)), .names = c("sample", "data1", "data2", "datest", "dattestr",      "add"), row.names = c(na, -3l), class = "data.frame"))  my_list [[1]]   sample data1 data2 data3 data1namet data2namab dataame  ma 1      2    56    59    90       sam1      test2     ex3 jay 2      6    78    27    28       sam1      test2     ex3 jay  [[2]]   sample data1 data2 datest dattestr add 1     12    56    59   exa9      cz1   2 2     13    78    27   exa9      cz1   2 3     17     3     2   exa9      cz1   2 

i've got 2 problems: extract columns in list based on patterns of column names, e.g. columns contain word 'data' in column name. wasn't able find solution grep.

i know how extract 1 column based on index number (see example below), how selection directly based on column name (not column number)?

out <- lapply(my_list, `[`, 1) # extract "sample" column 

try

lapply(my_list, function(df) df[, grep("data", names(df), fixed = true)] ) # [[1]] # data1 data2 data3 data1namet data2namab dataame # 1    56    59    90       sam1      test2     ex3 # 2    78    27    28       sam1      test2     ex3 #  # [[2]] # data1 data2 # 1    56    59 # 2    78    27 # 3     3     2  lapply(my_list, "[", "sample") # [[1]] # sample # 1      2 # 2      6 #  # [[2]] # sample # 1     12 # 2     13 # 3     17