0.1 Kiểm tra xem kiểu dữ liệu thuộc kiểu strings trong dataframe (categorical)

print_unique_col_value <- function(df) {
  for (col_name in colnames(df)) {
    column <- df[[col_name]]
    if (is.factor(column) || is.character(column)) {
      cat("Column name:", col_name, "\n")
      cat("Unique values:\n")
      print(unique(column))
      cat("\n")
    }
  }
}

print_unique_col_value(df)
LS0tDQp0aXRsZTogIkVuZC10by1FbmQtRnJhbWV3b3JrIg0KYXV0aG9yOiAiTmd1eWVuQmluaFBodW9uZ1V5ZW4iDQpkYXRlOiAiMjAyNC0wNi0xOSINCm91dHB1dDoNCiAgYm9va2Rvd246Omh0bWxfZG9jdW1lbnQyOg0KICAgIHRvYzogdHJ1ZQ0KICAgIG51bWJlcl9zZWN0aW9uczogdHJ1ZQ0KICAgIHRvY19mbG9hdDoNCiAgICAgIGNvbGxhcHNlZDogZmFsc2UNCiAgICBjc3M6ICJ0aWV1bHVhbi5jc3MiDQogICAgY29kZV9mb2xkaW5nOiBzaG93DQogICAgY29kZV9kb3dubG9hZDogdHJ1ZQ0KLS0tDQoNCmBgYHtyIHNldHVwLCBpbmNsdWRlPUZBTFNFfQ0Ka25pdHI6Om9wdHNfY2h1bmskc2V0KGVjaG8gPSBUUlVFKQ0KYGBgDQoNCiMjIEtp4buDbSB0cmEgeGVtIGtp4buDdSBk4buvIGxp4buHdSB0aHXhu5ljIGtp4buDdSBzdHJpbmdzIHRyb25nIGRhdGFmcmFtZSAoY2F0ZWdvcmljYWwpDQpgYGB7cn0NCg0KcHJpbnRfdW5pcXVlX2NvbF92YWx1ZSA8LSBmdW5jdGlvbihkZikgew0KICBmb3IgKGNvbF9uYW1lIGluIGNvbG5hbWVzKGRmKSkgew0KICAgIGNvbHVtbiA8LSBkZltbY29sX25hbWVdXQ0KICAgIGlmIChpcy5mYWN0b3IoY29sdW1uKSB8fCBpcy5jaGFyYWN0ZXIoY29sdW1uKSkgew0KICAgICAgY2F0KCJDb2x1bW4gbmFtZToiLCBjb2xfbmFtZSwgIlxuIikNCiAgICAgIGNhdCgiVW5pcXVlIHZhbHVlczpcbiIpDQogICAgICBwcmludCh1bmlxdWUoY29sdW1uKSkNCiAgICAgIGNhdCgiXG4iKQ0KICAgIH0NCiAgfQ0KfQ0KDQpwcmludF91bmlxdWVfY29sX3ZhbHVlKGRmKQ0KDQoNCmBgYA0KDQo=