CODEWITHSUNDEEP
pythontext
ali
ali

Reputation: 51

wrong format of generated text file in python

I have a big parent list containing many lists of tuples like the small example:

[
[('id', 'name', 'Trans'), ('ENS001', 'EGSB', 'TTP')], 
[('id', 'name', 'Trans'), ('EN02', 'EHGT', 'GFT')]
]

My goal is to make a text file in which there would some columns. The columns are the second tuple of each list in the parent list. The first tuple in all lists are similar in all nested lists and they would be column names.

I used this code(z is above list) 

rows= [i[1] for i in z]

to get 

[('ENS001', 'EGSB', 'TTP'), ('EN02', 'EHGT', 'GFT')]

And this one (which I call it “A”)

with open('out.txt','w') as f :
    f.write (' '.join(z[0][0]))
    for i in rows:
        f.write (' '.join(i))

to get the file. But in the file the columns are not separated like this.

id       name   Trans
ENS001   EGSB   TTP
EN02     EHGT   GFT

Upvotes: 2

Views: 363

Answers (3)

Padraic Cunningham
Padraic Cunningham

Reputation: 180522

You are writing it all on one line, you need to add a newline:

rows = (sub[1] for sub in z)


with open('out.txt','w') as f:
    f.write ("{}\n".format(' '.join(z[0][0]))) # add a newline
    for i in rows:
        f.write ("{}\n".format(' '.join(i))) # newline again

If you always have three elements in your rows and you want them aligned:

rows = [sub[1] for sub in z]


mx_len = 0

for tup in rows:
    mx = len(max(tup[:-1],key=len))
    if mx > mx_len:
        mx_len = mx

with open('out.txt', 'w') as f:
    a, b, c = z[0][0]
    f.write("{:<{mx_len}} {:<{mx_len}} {}\n".format(a, b, c, mx_len=mx_len))
    for a, b, c in rows:
        f.write("{:<{mx_len}} {:<{mx_len}} {}\n".format(a, b, c, mx_len=mx_len))

Output:

id     name   Trans
ENS001 EGSB   TTP
EN02   EHGT   GFT

If the length varies:

with open('out.txt', 'w') as f:
    f.write(("{:<{mx_len}}"*len(z[0][0])).format(*z[0][0], mx_len=mx_len) + "\n")
    for row in rows:
        f.write(("{:<{mx_len}}"*len(row)).format(*row, mx_len=mx_len) + "\n")

Upvotes: 2

Alex Martelli
Alex Martelli

Reputation: 882691

If you want to align column with spaces, first you have to determine what each column's width will be -- presumably the length of the longer header or content of each column, e.g:

wids = [len(h) for h in z[0][0]]
for i in rows:
    wids = [max(len(r), w) for w, r in zip(wids, i)]

Then on this basis you can prepare a format string, such as

fmt = ' '.join('%%%ds' % w for w in wids) + '\n'

and finally, you can write things out:

with open('out.txt','w') as f:
    f.write(fmt % z[0][0])
    for i in rows:
        f.write(fmt % i)

Upvotes: 1

WAF
WAF

Reputation: 1013

If you want the output to be separated by tabs like this you can join on \t, rather than ' ', which you are using. The bottom line of your code would look like f.write('\t'.join(i)).

Upvotes: 0

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