Check if string contains only whitespace

Question

How can I test if a string contains only whitespace  Example strings    quot     quot   space  space  space    quot   t  n  quot   space  tab  space  newline  space    quot  n n n t n quot   newline  newline  newline  tab  newline

User · Answer

Here is an answer that should work in all cases:

def is_empty(s):
    "Check whether a string is empty"
    return not s or not s.strip()

If the variable is None, it will stop at not sand not evaluate further (since not None == True). Apparently, the strip()method takes care of the usual cases of tab, newline, etc.

User · Answer

Use the str isspace   method   Return True if there are only whitespace characters in the string and there is at least one character  False otherwise  A character is whitespace if in the Unicode character database  see unicodedata   either its general category is Zs     Separator  space      or its bidirectional class is one of WS  B  or S   Combine that with a special case for handling the empty string  Alternatively  you could use str strip   and check if the result is empty

User · Answer

Resemblence with c  string static method isNullOrWhiteSpace    def isNullOrWhiteSpace str        Indicates whether the specified string is null or empty string       Returns  True if the str parameter is null  an empty string      or contains       whitespace  Returns false otherwise       if  str is None  or  str        or  str isspace         return True   return False  isNullOrWhiteSpace None  - gt  True    None equals null in c   java  php isNullOrWhiteSpace       - gt  True isNullOrWhiteSpace       - gt  True

User · Answer

You want to use the isspace   method     str isspace        Return true if there are only whitespace characters in the string and   there is at least one character  false otherwise    That s defined on every string object  Here it is an usage example for your specific use case   if aStr and  not aStr isspace         print aStr

User · Answer

To check if a string is just a spaces or newline  Use this simple code  mystr           n   r   t     if not mystr strip      The String Is Only Spaces      print   n    Invalid String           exit 1  mystr   mystr strip   print   n    Your String Is    mystr

User · Answer

I m assuming in your scenario  an empty string is a string that is truly empty or one that contains all white space   if str strip         print  string is not empty   else      print  string is empty     Note this does not check for None

User · Answer

str isspace   returns False for a valid and empty string  gt  gt  gt  tests     foo          r n t        gt  gt  gt  print  s isspace   for s in tests    False  True  True  False   Therefore  checking with not will also evaluate None Type and    or  quot  quot   empty string   gt  gt  gt  tests     foo          r n t       None   quot  quot    gt  gt  gt  print   not s or s isspace   for s in tests    False  True  True  True  True  True

User · Answer

I used following    if str and not str isspace      print  not null and not empty nor whitespace   else    print  null or empty or whitespace

User · Answer

You can use the str isspace   method

User · Answer

for those who expect a behaviour like the apache StringUtils isBlank or Guava Strings isNullOrEmpty    if mystring and mystring strip        print  not blank string  else      print  blank string

User · Answer

Check the length of the list given by of split   method   if len your string split    0       print  yes     Or Compare output of strip   method with null   if your string strip               print  yes

[python] Check if string contains only whitespace

Examples related to python

Examples related to text

Examples related to whitespace