Remove spaces and tabs within a string in python

Looks like you want to remove the whitespace from the start of lines, and remove all whitespace before a colon. Use regular expressions:

import re

re.sub(r'(^[ \t]+|[ \t]+(?=:))', '', str1, flags=re.M)

This picks out spaces and tabs at the start of lines (^[ \t]*, ^ is the start of a line, [ \t] is a space or tab, + is 1 or more), or it picks out spaces and tabs right before a colon ([ \t]+ is 1 or more spaces and tabs, (?=:) means that a : character must follow but isn't included in what is picked) and then replaces those spaces and tabs with an empty string. The flags=re.M is there to make sure the pattern works on each individual line.

Demo:

>>> import re
>>> str1 = """vendor_id\t: GenuineIntel
...         cpu family\t: 6
...         model\t\t: 58
...         model name\t: Intel(R) Core(TM) i3-3120M CPU @ 2.50GHz
...         stepping\t: 9
...         cpu MHz\t\t: 2485.659
...         cache size\t: 6144 KB
...         fpu\t\t: yes
...         fpu_exception\t: yes
...         cpuid level\t: 5
...         wp\t\t: yes"""
>>> print re.sub(r'(^[ \t]+|[ \t]+(?=:))', '', str1, flags=re.M)
vendor_id: GenuineIntel
cpu family: 6
model: 58
model name: Intel(R) Core(TM) i3-3120M CPU @ 2.50GHz
stepping: 9
cpu MHz: 2485.659
cache size: 6144 KB
fpu: yes
fpu_exception: yes
cpuid level: 5
wp: yes

If your input string does not have leading whitespace (and you just indented your sample yourself to make it look lined up), then all you want to remove is tabs:

str1 = str1.replace('\t', '')

and be done with it.

I don't know what you mean by "randomly", but you can remove all tabs with:

str1 = str1.replace("\t", "")

This will solve your answer:

str1 = """vendor_id\t: GenuineIntel
    cpu family\t: 6
    model\t\t: 58
    model name\t: Intel(R) Core(TM) i3-3120M CPU @ 2.50GHz
    stepping\t: 9
    cpu MHz\t\t: 2485.659
    cache size\t: 6144 KB
    fpu\t\t: yes
    fpu_exception\t: yes
    cpuid level\t: 5
    wp\t\t: yes"""
arr = [line.strip() for line in str1.split('\n')]
for line in arr:
    print line.strip()

def invitation_ics():
    text = f"""BEGIN:VCALENDAR
CLASS:PUBLIC
STATUS:CONFIRMED
    """ # text
return text

out not tab Output: BEGIN:VCALENDAR CLASS:PUBLIC STATUS:CONFIRMED

str1 = str1.replace("\t", "").replace(" ", "")

it would replace the tabs first and then white spaces.