小编Gra*_*vel的帖子

我不明白为什么 Pandas 数据框会四舍五入我的列中的值，我将其他两列的值相除。我希望新列中的数字带有两位小数，但这些值是四舍五入的。我检查了列的 dtypes，两者都是“float64”。

import pandas as pd
import numpy as np


# CURRENT DIRECTORY 
cd = os.path.dirname(os.getcwd())

# concatenate csv files
dfList = []

for root, dirs, files in os.walk(cd):
    for fname in files:
        if re.match("output_contigs_SCMgenes.csv", fname):
            frame = pd.read_csv(os.path.join(root, fname))
            dfList.append(frame)    

df = pd.concat(dfList)

#replace nan in SCM column with 0
df['SCM'].fillna(0, inplace=True)

#add column with genes/SCM
df['genes/SCM'] = df['genes']/df['SCM']

输出如下：

    genome  contig  genes  SCM  genes/SCM
0    20900      48      1    0        inf
1    20900      37    130  103          1 …

我有一个文件“specieslist.txt”，其中包含以下信息：

Bacillus,genus
Borrelia,genus
Burkholderia,genus
Campylobacter,genus

现在，我希望 python 在第一列（在本例中为“弯曲杆菌”）中查找变量并返回第二列（“属”）的值。我写了以下代码

import csv
import pandas as pd

species_import = 'Campylobacter'
df = pd.read_csv('specieslist.txt', header=None, names = ['species', 'level'] )
input = df.loc[df['species'] == species_import]
print (input['level'])

但是，我的代码返回太多，而我只想要“属”

3    genus
Name: level, dtype: object

使用我的代码,我循环遍历文件并计算文件中的模式.我的代码如下

from collections import defaultdict
import csv, os, re
from itertools import groupby
import glob


   def count_kmers(read, k):
        counts = defaultdict(list)
        num_kmers = len(read) - k + 1
        for i in range(num_kmers):
            kmer = read[i:i+k]
            if kmer not in counts:
                counts[kmer] = 0
            counts[kmer] += 1
        for item in counts:
            return(basename, sequence, item, counts[item])

    for fasta_file in glob.glob('*.fasta'):
        basename = os.path.splitext(os.path.basename(fasta_file))[0]
        with open(fasta_file) as f_fasta:
            for k, g in groupby(f_fasta, lambda x: x.startswith('>')):
                if k:
                    sequence = next(g).strip('>\n')
                else:
                    d1 …