格式化CSV数据输出？

Question

I'm fairly new to python and made something that had this output: (The text is in a csv file so so: 1,A 2,B 3,C etc)

Number        Letter

1             A
2             B
3             C
26            Z

Unfortunately, I spent a good amount of time making it using a complicated method in which I manually made spaces like this: Updated Code rn

fx = int(input('Number?\n'))
f=open('nums.txt','r')
lines=f.readlines()
line = lines[fx - 1]
with open('nums.txt','r') as f:
    for i, line in enumerate(f):
        if i >= 5: 
            break
        NUM, LTR, SMB = line.rsplit(',', 1)
        print(NUM.ljust(13) + LTR.ljust(13) + SMB)

How do I get it to make 3 columns? Right now it comes up with a

ValueError: not enough values to unpack (expected 3, got 2) 

---

So is there a simpler method of achieving this that doesn't move the strings around like this:

Number        Letter

1             A
2             B
3             C
26             Z #< string moves with spaces.

Answer 1

For simple alignment, you can use ljust or rjust . There is also no need to read the entire file for each line you want to process:

with open('numberletter','r') as f:
    for i, line in enumerate(f):
        if i >= 5: 
            break
        number, letter = line.rsplit(',', 1)
        print(number.ljust(13) + letter)

For more complex output formatting, look at str.format() and the formatting syntax

Answer 2

You can use sys module for that.

import sys
a=[1,"A"]
sys.stdout.write("%-6s %-50s " % (a[0],a[1]))