使用Python将CSV文件转换为固定宽度文件

Question

如何将CSV转换为固定宽度的文件格式。在

import csv
with open('C:\\Users\\thara.savio\\Downloads\\Sacramentorealestatetransactions.csv', newline='') as csvfile:
    spamreader = csv.reader(csvfile, delimiter=',')
    for row in spamreader:
        print('     '.join(row))

它转换为文本文件，其中制表符作为分隔符，而不是固定宽度格式。在

下面是我得到的结果。在

^{pr2}$

Answer 1

可以对数据进行预处理以获得每列的最大宽度 并使用string format mini language编写文件：

data = """3526 HIGH ST, SACRAMENTO, 95838, CA, 2, 1, 836, Residential, Wed May 21 00:00:00 EDT 2008, 59222, 38.631913, -121.434879
51 OMAHA CT, SACRAMENTO, 95823, CA, 3, 1, 1167, Residential, Wed May 21 00:00:00 EDT 2008, 68212, 38.478902, -121.431028
2796 BRANCH ST, SACRAMENTO, 95815, CA, 2, 1, 796, Residential, Wed May 21 00:00:00 EDT 2008, 68880, 38.618305, -121.443839
2805 JANETTE WAY, SACRAMENTO, 95815, CA, 2, 1, 852, Residential, Wed May 21 00:00:00 EDT 2008, 69307, 38.616835, -121.439146
6001 MCMAHON DR, SACRAMENTO, 95824, CA, 2, 1, 797, Residential, Wed May 21 00:00:00 EDT 2008, 81900, 38.51947, -121.435768"""

# max-width per column, column == key, width == value
w = {}
lines = data.splitlines()
for line in lines:
    for col_nr, col in enumerate(line.strip().split(",")):
        w[col_nr] = max( w.get(col_nr,0), len(col))

# w == {0: 16, 1: 11,  2:  6, 3: 3,   4:  2,   5: 2, 
#       6:  5, 7: 12,  8: 29, 9: 6,  10: 10,  11: 12}

# write file
with open("file.txt","w") as f:
    for line in lines:
        for col_nr, col in enumerate(line.strip().split(",")):
            # the :<{w[col_nr]+5}} - part is left-adjusting to certain width 
            f.write(f"{col:<{w[col_nr]+5}}") # 5 additional spaces
        f.write("\n")

with open("file.txt","r") as f:
    print(f.read())

输出：

^{pr2}$

Answer 2

您可以在类别中找到最长的值，并根据长度添加缓冲区间距：

data = """
3526 HIGH ST, SACRAMENTO, 95838, CA, 2, 1, 836, Residential, Wed May 21 00:00:00 EDT 2008, 59222, 38.631913, -121.434879
51 OMAHA CT, SACRAMENTO, 95823, CA, 3, 1, 1167, Residential, Wed May 21 00:00:00 EDT 2008, 68212, 38.478902, -121.431028
2796 BRANCH ST, SACRAMENTO, 95815, CA, 2, 1, 796, Residential, Wed May 21 00:00:00 EDT 2008, 68880, 38.618305, -121.443839
2805 JANETTE WAY, SACRAMENTO, 95815, CA, 2, 1, 852, Residential, Wed May 21 00:00:00 EDT 2008, 69307, 38.616835, -121.439146
6001 MCMAHON DR, SACRAMENTO, 95824, CA, 2, 1, 797, Residential, Wed May 21 00:00:00 EDT 2008, 81900, 38.51947, -121.435768
"""
new_data = [i.split(', ') for i in filter(None, data.split('\n'))]

---

^{pr2}$

输出：

3526 HIGH ST     SACRAMENTO 95838 CA 2 1 836  Residential Wed May 21 00:00:00 EDT 2008 59222 38.631913 -121.434879
51 OMAHA CT      SACRAMENTO 95823 CA 3 1 1167 Residential Wed May 21 00:00:00 EDT 2008 68212 38.478902 -121.431028
2796 BRANCH ST   SACRAMENTO 95815 CA 2 1 796  Residential Wed May 21 00:00:00 EDT 2008 68880 38.618305 -121.443839
2805 JANETTE WAY SACRAMENTO 95815 CA 2 1 852  Residential Wed May 21 00:00:00 EDT 2008 69307 38.616835 -121.439146
6001 MCMAHON DR  SACRAMENTO 95824 CA 2 1 797  Residential Wed May 21 00:00:00 EDT 2008 81900 38.51947  -121.435768