R

library(Matrix)
matrix_dir = "/home/li/"
barcode.path <- paste0(matrix_dir, "barcodes.tsv")
features.path <- paste0(matrix_dir, "features.tsv")
matrix.path <- paste0(matrix_dir, "matrix.mtx")
mat <- readMM(file = matrix.path)
feature.names = read.delim(features.path, 
                       header = FALSE,
                       stringsAsFactors = FALSE)
barcode.names = read.delim(barcode.path, 
                       header = FALSE,
                       stringsAsFactors = FALSE)
colnames(mat) = barcode.names$V1
rownames(mat) = feature.names$V1

Python

import csv
import gzip
import os
import scipy.io
matrix_dir = "/home/li/"
mat = scipy.io.mmread(os.path.join(matrix_dir, "matrix.mtx"))
features_path = os.path.join(matrix_dir, "features.tsv")
feature_ids = [row[0] for row in csv.reader(open(features_path), delimiter="\t")]
gene_names = [row[1] for row in csv.reader(open(features_path), delimiter="\t")]
feature_types = [row[2] for row in csv.reader(open(features_path), delimiter="\t")]
barcodes_path = os.path.join(matrix_dir, "barcodes.tsv")
barcodes = [row[0] for row in csv.reader(open(barcodes_path), delimiter="\t")]