python练习题01 碱基统计

[root@PC1 test01]# ls
a.fa
[root@PC1 test01]# cat a.fa      ## 测试fasta文件
AGCTTTTCATTCTGACTGCAACGGGCAATATGTCTCTGTGTGGATTAAAAAAAGAGTGTCTGATAGCAGC

[root@PC1 test01]# ls
a.fa  count.py
[root@PC1 test01]# cat count.py     ## 统计程序
#!/usr/bin/env python
# -*- coding: utf-8 -*-

in_file = open("a.fa", "r")
a = 0; c = 0; g = 0; t = 0
for i in in_file:
        i = i.strip()
        for j in i:
                if j == "A":
                        a += 1
                elif j == "C":
                        c += 1
                elif j == "G":
                        g += 1
                elif j == "T":
                        t += 1
                else:
                        print("anomanous letter!" + j)
                        break
#in_file.close()
print(a, c, g, t)

[root@PC1 test01]# ls
a.fa  count.py
[root@PC1 test01]# cat a.fa            ## 测试文件
AGCTTTTCATTCTGACTGCAACGGGCAATATGTCTCTGTGTGGATTAAAAAAAGAGTGTCTGATAGCAGC
[root@PC1 test01]# python3 count.py    ## 执行程序
20 12 17 21

[root@PC1 test01]# ls
a.fa  count.py
[root@PC1 test01]# cat a.fa       ## 测试数据
AGCTTTTCATTCTGACTGCAACGGGCAATATGTCTCTGTGTGGATTAAAAAAAGAGTGTCTGATAGCAGC
[root@PC1 test01]# cat count.py     ## 统计程序
#!/usr/bin/env python
# -*- coding: utf-8 -*-

in_file = open("a.fa", "r")
file = in_file.read()

print(file.count("A"), file.count("C"), file.count("G"), file.count("T"))
[root@PC1 test01]# python3 count.py    ## 执行程序
20 12 17 21